最早区块链的论文是什么,最早区块链的论文有哪些

最早的区块链论文是2008年由中本聪（Satoshi Nakamoto）撰写的《比特币：一种点对点的电子现金系统》，这篇论文开启了区块链技术的发展历程。拓展3个相关关键词，分别是“比特币”、“分布式账本”、“智能合约”。

比特币：比特币（Bitcoin）是一种去中心化的虚拟货币，它是使用区块链技术运行的第一种虚拟货币。比特币是中本聪在2008年撰写的《比特币：一种点对点的电子现金系统》中提出的，它是一种基于密码学的货币，其交易是在分布式账本（区块链）上记录的，并且可以被任何人查询。比特币是一种虚拟货币，它不受任何中央机构或政府的控制，它拥有自己的价值，可以在交易中使用，也可以作为投资工具。

分布式账本：分布式账本（Distributed Ledger）是一种分布式的数据库，它可以被分散的节点共同维护，每个节点都可以拥有完整的账本副本，而不需要依赖中央服务器。分布式账本是区块链技术的核心，它记录了所有的交易，并且可以被任何人查询。它的特点是去中心化、不可篡改、安全可靠，因此被广泛应用于金融、政府、医疗等领域。

智能合约：智能合约（Smart Contract）是一种可以自动执行的电子合约，它可以实现自动转账、自动结算等功能，它可以替代传统的合约，使得交易更加安全、高效。智能合约是基于区块链技术的，它可以被所有节点共同维护，并且不受任何中央机构或政府的控制，因此它可以更好地保护交易双方的利益。智能合约的应用范围很广，它可以应用于金融、政府、医疗等领域，以及更多的新兴领域，如物联网、智能制造等。

以上就是关于最早区块链论文的3个相关关键词：比特币、分布式账本、智能合约的介绍，希望能够帮助大家对区块链技术有更深入的了解。

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『一』How to interpret blockchain in the simplest way

Everyone hears the word blockchain every day recently, so what is blockchain? Explanations such as "distributed, difficult to tamper, and consistent storage" are too technical and dry. Let me give you some popular science here: Blockchain is mainly designed to solve the trust problem between individuals who do not trust each other.

To give a popular example: It is said that Lao Li and Lao Wang live in the same village. Lao Li is a little short of money recently and wants to borrow some money from Lao Wang. As for Lao Wang, he was worried about what would happen if he defaulted on the loan after borrowing money from Lao Li, so he called in the "highly respected" village chief. But thinking about it, the village chief couldn't be trusted either. The village chief had even stolen other people's sweet potatoes in the past! what to do?

The blockchain method is: After Lao Wang borrowed 1,000 yuan from Lao Li, he then used a loudspeaker to shout in the village, "I, Lao Wang, borrowed 1,000 yuan from Lao Li today. Everyone Record it quickly." So everyone in the village recorded it in their own account books and kept it carefully. This is good, Lao Li can't rely on him anymore. Even if there are dishonest people in the village, there are still many good people. Lao Li can't find everyone in the village to secretly erase his loan records. In this way, the blockchain solved the trust problem of borrowing money between Lao Wang and Lao Li, who did not trust each other.

Before the emergence of blockchain, how did we solve the problem of trust between individuals who did not trust each other? It's simple, just find a "witness" who is "highly respected" and trusted by both parties, such as the village chief in the story, such as Alipay between the buyer and seller, such as the notary office, etc. However, it is possible that such "witnesses" may not always be honest, so the blockchain simply allows everyone to act as a witness.

Lao Wang is relieved, but Lao Li has a headache! Lao Li has to wait until everyone in the village has recorded the money before he can get the money lent to him. There is no uncle or aunt in the family who is slower. Therefore, there is still a certain distance between blockchain and application, and efficiency issues need to be significantly improved.

Recall how you usually trade with others: you can choose a beautiful dress in a physical store, confirm that the other party’s clothes are of good quality, and the other party confirms that your money is real money. , then we will pay and receive the goods face to face.

What if we are thousands of miles apart and neither know nor trust each other but still want to trade? Then there needs to be a third party that we all trust, which is the so-called consensus mechanism. For example: you can complete the transaction through a third-party witness guarantee on Taobao. The money is first given to Alipay - Alipay collects the payment and lets the seller deliver the goods - the seller delivers the goods - you confirm receipt - Alipay then gives the money to the seller.

However, what if this centralized organization does evil, and Dad Ma tears up the account books and refuses to admit that you gave the money, or joins forces with the seller to defraud you of money?

Or the government borrowed 1 million from you and finally used the method of over-issuance of currency.If I give you the money back, 1 million shrinks to 10,000, and you have to bear the loss of inflation, what will you do?

Is there a third party that is not controlled by any government or organization, can complete arbitration in an open and transparent manner, has records that will not be tampered with, and has no risk of running away?

Don’t worry, our protagonist blockchain technology solves this problem - the transactions between you can be witnessed by everyone in this blockchain system, and everyone’s small ledger will be recorded Your deal. If B denies receiving money from A, or if A says that he borrowed 300 yuan, passers-by A, B, B, and D will question him. How exactly is it done?

1) The system issues a small ledger to everyone, so that everyone has the right to keep accounts. We call it distributed accounting.

2) In order to encourage everyone to help others keep accounts, the system code is set to reward tokens such as Bitcoin to the keepers. In order to prevent a group of people from being blocked in keeping accounts, the tokens are also set to There are only a limited number of A, B, C and D who need to be calculated through the mechanism specified by the system. Only the fastest and best calculation can obtain the right to keep accounts. After recording, it is broadcast to everyone through the system. Everyone copies the same ledger. This is obtained through calculation. The reward process is called mining, and passers-by A, B, C and D who keep accounts are the miners.

3) One day, A, who originally recorded the transaction, Game Over, but the ledger still exists in other people's ledgers. Neither A nor B can deny it. We have written in code how to arbitrate and distribute, without the need for banks, governments, enterprises and other centralized organizations to serve as third-party witnesses (decentralization), and the direct point-to-point (P2P) transaction method is called decentralization.

4) The system packages multiple transactions into blocks and links them in chronological order to become the final ledger that everyone has. This is the blockchain technology

In fact, the block chain The simple understanding of blockchain as a ledger is only the simplest interpretation. If each of its characteristics is separated, it can be applied in many fields.

Now the traditional financial industry, securities firms, and investment institutions are rushing to enter the Internet of Things, games, storage, copyright, anti-counterfeiting, credit reporting, payment, prediction markets (gambling, etc.), communities and many other fields. The exploration and application of blockchain has already begun.

The Internet allows everything to be connected. Can blockchain make everything connected trustworthy?

Let me explain the blockchain using the natural stones of heaven and earth:

All science, philosophy, morality... heaven and earth are included. Every thing and every culture is related to the Taoism of heaven and earth.

Blockchain naturally cannot escape the fate of heaven and earth: that is, smooth, random, infinite, and impermanent.

It is this strange stone, and the overall data movement on its surface. First, the whole is intangible. Second, the lines and points adhere to a pattern: the path of impermanence. That is to say, every line and every point they pursue is not a closed goal or a limited purpose. I can understand it better when I say this: when a painter paints a chicken, it has a purpose and an ending, while strange rocks, when created by nature, have no ending. Therefore, the phase is not closed, and the line and point data are not terminated. The technology of block connection is this way of destiny. Impermanence is invisible and has no end. (No centralization means formlessness, no closed form, no closed structure, no closed mind... just like "stone" to do things).

Confucius Lingshi Museum in Qufu, Shandong

Hello everyone, I am Pippi. I will use a few life examples to explain to you what blockchain is?

A decentralized, tamper-proof, distributed storage data block linking system that uses encrypted information as the link address is called blockchain

This thing is originally There are many high-tech composite products that cannot be simplified. No matter how simple it is, it takes a long paragraph, and it may not be clear.

The strict definition of blockchain refers to the design based on cryptography technology. Consensus mechanism, a distributed database technology in which multiple nodes in a peer-to-peer network jointly maintain a continuously growing, chained list ledger constructed of timestamps and ordered record data blocks. This technical solution allows any number of nodes participating in the system to calculate and record all information exchange data in the system over a period of time into a data block (block) through cryptographic algorithms, and generate the fingerprint of the data block for linking ( chain) and check the next data block, all participating nodes in the system jointly determine whether the record is true.

Blockchain is a general term for technical solutions similar to NoSQL (non-relational database). It is not a specific technology. Blockchain technology can be implemented through many programming languages ​​and architectures. . There are also many ways to implement blockchain. Common ones currently include POW (Proof of Work), POS (Proof of Stake), DPOS (Delegate Proof of Stake), etc.

The concept of blockchain was first proposed in the paper "Bitcoin: A Peer-to-Peer Electronic Cash System" by the author who calls himself Satoshi Nakamoto (Satoshi Nakamoto) individual (or group). Therefore, Bitcoin can be regarded as the first financial application of blockchain.Applications in the payment field.

[Popular explanation]

No matter how big the system or how small the website, there is usually a database behind it. So who will maintain this database? Under normal circumstances, whoever is responsible for operating the network or system will maintain it. If it is a WeChat database, it must be maintained by Tencent's team, and Taobao's database must be maintained by Alibaba's team. Everyone must think that this approach is natural, but this is not the case with blockchain technology.

If we imagine the database as a ledger: Alipay, for example, is a typical ledger, and any change in data is an accounting type. We can think of database maintenance as a very simple accounting method. The same is true in the world of blockchain. Everyone in the blockchain system has the opportunity to participate in accounting. The system will select within a period of time, maybe within ten seconds, or maybe ten minutes, to select the person with the fastest and best accounting during this period. This person will do the accounting, and he will combine the changes in the database during this period with Changes in the ledger are recorded in a block. We can imagine this block as a page of paper. After confirming that the record is correct, the system will link (chain) the data fingerprint of the past ledger to this paper, and then This piece of paper is sent to everyone else in the entire system. Then the cycle starts over and the system looks for the next person who can do the accounting quickly and well, and everyone else in the system gets a copy of the entire ledger. This also means that everyone in this system has exactly the same ledger. This technology is called blockchain technology, also known as distributed ledger technology.

Since everyone (computer) has exactly the same ledger, and everyone (computer) has exactly the same rights, there will be no problem due to a single person (computer) losing contact or going down. The entire system collapses. Since there are exactly the same ledgers, it means that all data is open and transparent, and everyone can see the digital changes in each account. Its very interesting feature is that the data in it cannot be tampered with. Because the system will automatically compare, it will consider the account books with the largest number of the same number as the real account books, and the small number of account books with different numbers as others are false account books. In this case, it makes no sense for anyone to tamper with their own ledger, because unless you can tamper with most of the nodes in the entire system. If the entire system has only five or ten nodes, it may be easy to do, but if there are tens of thousands or even hundreds of thousands of nodes, and they are distributed in any corner of the Internet, unless someone can control most of the computers in the world , otherwise it would be unlikely to tamper with such a large blockchain.

[Elements]

Combined with the definition of blockchain, we believe that it must have the following four elements to be called a public blockchain technology. If it only has the first three points elements, which we will consider privateThere is blockchain technology (private chain).

1. Point-to-point peer-to-peer network (peer-to-peer power, physical point-to-point connection)

2. Verifiable data structure (verifiable PKC system, non-tamperable database)

3. Distributed consensus mechanism (solve the Byzantine generals problem and double payment)

4. Nash equilibrium game design (cooperation is an evolutionarily stable strategy)
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[Characteristics]

Combined with the definition of blockchain, blockchain will realize four main characteristics: decentralized, trustless, Collectively maintained (Collectively maintained), reliable database (Reliable Database). And the four characteristics will lead to two other characteristics: open source (Open Source) and privacy protection (Anonymity). If a system does not possess these characteristics, it will not be considered an application based on blockchain technology.

Decentralized: The entire network has no centralized hardware or management organization. The rights and obligations between any nodes are equal, and the damage or loss of any node will not affect it. operation of the entire system. Therefore, the blockchain system can also be considered to have excellent robustness.

Trustless: Each node participating in the entire system does not need to trust each other for data exchange. The operating rules of the entire system are open and transparent, and all data contents are also public. , therefore within the rule range and time range specified by the system, nodes cannot and cannot deceive other nodes.

Collectively maintain: The data blocks in the system are jointly maintained by all nodes with maintenance functions in the entire system, and these nodes with maintenance functions can be participated by anyone.

Reliable Database: The entire system will be divided into databases so that each participating node can obtain a copy of the complete database. Unless more than 51% of the nodes in the entire system can be controlled at the same time, modifications to the database on a single node are invalid and cannot affect the data content on other nodes. Therefore, the more nodes and stronger computing power participating in the system, the higher the data security in the system.

Open Source: Since the operating rules of the entire system must be open and transparent, for the program, the entire system must be open source.

PrivacyProtection (Anonymity): Since there is no need for mutual trust between nodes, there is no need to disclose identities between nodes, and the privacy of each participating node in the system is protected.

[One of the meanings of blockchain: Solving the Byzantine Generals Problem]

The core problem solved by blockchain is not "digital currency", but information asymmetry and inconsistency. Under a certain environment, how to establish a "trust" ecological system that satisfies the occurrence and development of economic activities. This problem is called the "Byzantine Generals Problem", also known as "Byzantine Fault Tolerance" or the "Two Armies Problem". This is a difficult problem faced when information machines interact in a distributed system, that is, any point in the entire network When nodes cannot trust the other party they are communicating with, how can they create a consensus basis for secure information exchange without worrying about data being tampered with. Blockchain uses an algorithmic proof mechanism to ensure the security of the entire network. With it, all nodes in the entire system can automatically and securely exchange data in a trustless environment. For more introduction, please see "Bitcoin and the Byzantine Generals Problem".

[The second meaning of blockchain: realizing cross-border value transfer]

At the beginning of the birth of the Internet, the earliest core problem to be solved was information production and transmission. We can transfer information through the Internet It can be quickly generated and copied to every corner of the world with a network, but it still cannot solve the value transfer and credit transfer. The so-called value transfer here refers to a method that everyone in the network can recognize and confirm, accurately transferring a certain part of the value from a certain address to another address, and it must be ensured that when the value is transferred, the original address is reduced The transferred portion, while the new address increases the value transferred. The value mentioned here can be a monetary asset, or some kind of physical asset or virtual asset (including securities, financial derivatives, etc.). The results of this operation must be recognized by all participating parties, and the results cannot be manipulated by any one party.

There are also various financial systems in the current Internet, and there are also many payment systems provided by government banks or third parties, but they still rely on centralized solutions. The so-called centralized solution is to put all value transfer calculations on a central server (cluster) through the endorsement of a certain company or government credit. Although all calculations are automatically completed by the program, this centralization must be trusted. person or institution. In fact, through centralized credit endorsement, credit can only be limited to certain institutions, regions or countries. It can be seen from this that the fundamental problem that must be solved is credit. Therefore, the core issue of value transfer is transnational credit consensus.

In such a complex global system, it is difficult to establish a global credit consensus system out of thin air, because each countryThe political, economic and cultural conditions of each country are different, and it is almost impossible for the companies and governments of two countries to completely trust each other. This means that whether it is endorsed by the credit of individuals or corporate governments, the value between transnational Even if the exchange can be completed, it will have huge time and economic costs. But in the long history of mankind, no matter how different the religion, politics and culture of each country are, the only thing that can reach consensus is mathematics (basic science). Therefore, it is no exaggeration to say that mathematics (algorithms) is the greatest common denominator of global civilization and the basis for the greatest consensus among human beings around the world. If we use mathematical algorithms (programs) as endorsement, all rules are based on an open and transparent mathematical algorithm (program), which can allow all people with different political and cultural backgrounds to gain consensus.

[Future Development]

The Internet will make global interactions closer and closer, accompanied by a huge trust gap. Currently, the existing mainstream database technology architecture is private and centralized. On this architecture, the problems of value transfer and mutual trust can never be solved. Therefore, blockchain technology may become the next generation database architecture. Through decentralized technology, it will be possible to complete the huge progress of mathematical (algorithm) endorsement and global mutual trust on the basis of big data.

As a specific distributed access data technology, blockchain technology uses multiple nodes participating in calculations in the network to jointly participate in the calculation and recording of data, and mutually verify the validity of their information. (anti-counterfeiting). From this point of view, blockchain technology is also a specific database technology. The Internet has just entered the era of big data, but from the current point of view, big data is still in a very basic stage. But when it enters the blockchain database stage, it will enter the big data era of real strong trust endorsement. All data here has acquired indestructible quality, and no one has the ability or need to question it.

Perhaps we are now at a major turning point - the early stages of a major transition that is almost as profound as the changes brought about by the Industrial Revolution. Not only are new technologies exponential, digital and combined, progress and changes, but more surprises may be ahead of us. In the next 24 months, the planet will grow more computing power and record more data than it has in all of history combined. In the past 24 months, this value increase may have exceeded 1,000 times. This digital data information is growing faster than Moore's Law. Blockchain technology will not only be used in the field of financial payments, but will expand to all current applications, such as decentralized Weibo, WeChat, search, renting, and even taxi-hailing software may appear. Because blockchain will allow humans to collaborate on a large scale in a trustless manner without geographical restrictions.

Blockchain is a technology based on which there are many applications, includingIn all industries related to data and information, Bitcoin is one of the most well-known applications. The popular explanation of blockchain is that if you buy a lipstick online, you first find the product you like and place an order with the seller. You first give the money to the intermediary platform. After the seller ships the goods and the buyer confirms receipt, the intermediary platform then transfers the money. Transfer it to the seller, because of the trust issue, both buyers and sellers rely on the intermediate platform, and the blockchain, as a decentralized distributed ledger database, focuses on removing this intermediate platform while solving the trust issue at the same time. In the blockchain, everyone has their own ledger to record everything that happens. If a seller takes money but does not deliver the goods during the transaction, this record will exist permanently and cannot be modified, and there is no need to interact with each other. To exchange information, the blockchain world will select the person's ledger that records the fastest and best quality at the same time node to copy, send and connect in series, and finally stack it up to form a block.

When everyone talks about virtual currencies, they often cannot do without the concept of blockchain. So what is the magic of blockchain?

Blockchain is an underlying technology, essentially a decentralized distributed ledger database. It sounds very high-end and out of reach, but it is actually very easy to understand.

For example, if you want to buy something on Taobao, the first thing you usually have to do is to open Taobao, find the product you want, place an order and pay the money to Taobao, which is the transaction intermediary. Taobao will pay the seller after receiving the goods and confirming receipt. This was originally just a transaction between me and the seller, but it has an additional "center", namely Taobao.

During the transaction process, this "center" has unlimited power and can even modify the bill at will. Therefore, the “center” often needs a strong backend to endorse it.

So, a man named Satoshi Nakamoto wanted to get rid of this center with infinite power. He wanted to create a decentralized system in which everyone is the center and everyone is the center. Have the authority to keep accounts. So, he created Bitcoin.

In the Bitcoin system, everyone has a small ledger to record every transaction that occurs. A transaction is only valid after being confirmed by a majority of people. If the seller doesn't deliver the goods, everyone's little ledger will record it, leaving him nowhere to escape.

At this time, you may have questions. Since it is just a public ledger, why is it called a blockchain? This involves the issue of consensus. The blockchain system is a system composed of many "centers". The entire blockchain belongs to all individuals participating in accounting. At this time, new problems arise. A system must be in order to survive in the long term. If the bookkeeper can act recklessly regardless of the cost, it may happen that he originally just bought a mobile phone, but received a Tesla instead.

So, Satoshi Nakamoto invented a consensus method called PoW. This method increases the cost of bookkeeping for bookkeepers and prevents them from doing evil easily. PoW uses cryptography to require bookkeepers to compete for computing power to obtain accounting rights. The first bookkeeper to calculate the result can obtain the accounting rights of a block packaged from several transactions. At the same time, you will receive certain tokens as rewards. This is what we commonly call "mining".

Now that the bookkeeper has recorded a block containing several transactions, the system needs to be organized and sorted. It is impossible to have countless blocks distributed in the system in an orderly manner. So it is necessary to link all blocks end to end in chronological order. At this time, the blockchain was born. The core of blockchain is technology.

『二』The blockchain consensus mechanism is to let everyone in the system know what each other has done

1. What is the technology of blockchain? If we assume that the database To form a ledger, reading and writing the database can be regarded as an act of bookkeeping. The principle of blockchain technology is to find the person with the fastest and best bookkeeping within a period of time. This person will do the bookkeeping, and then the ledger will be This page of information is sent to everyone else in the entire system. This is equivalent to changing all the records in the database and sending them to every other node in the entire network, so blockchain technology is also called a distributed ledger. Blockchain refers to a technical solution that collectively maintains a reliable database through decentralization and trustlessness. This technical solution mainly allows any number of nodes participating in the system to associate and generate a series of data blocks (blocks) using cryptographic methods. Each data block contains all the information exchange data of the system within a certain period of time, and generates The data fingerprint is used to verify the validity of its information and chain to the next database block. Blockchain is a general term for technical solutions similar to NoSQL (non-relational database). It is not a specific technology and can be implemented through many programming languages ​​and architectures. There are also many ways to implement blockchain. Common ones currently include POW (Proof of Work), POS (Proof of Stake), DPOS (Delegate Proof of Stake), etc. The concept of blockchain was first proposed in the paper "Bitcoin: A Peer-to-Peer Electronic Cash System", written by an individual who calls himself Satoshi Nakamoto (or group). Therefore, Bitcoin can be regarded as the first application of blockchain in the field of financial payments. 2. What is the principle of blockchain? Combined with the definitionThe definition of blockchain requires these four characteristics before we can consider it: decentralized, trustless, collectively maintained, and reliable database. And the four characteristics will lead to two other characteristics: open source (Open Source) and anonymity (Anonymity). If a system does not possess these characteristics, it will not be considered an application based on blockchain technology. Decentralized: The entire network has no centralized hardware or management organization. The rights and obligations between any nodes are equal, and the damage or loss of any node will not affect the operation of the entire system. Therefore, the blockchain system can also be considered to have excellent robustness. Trustless: Data exchange between each node in the entire system does not require mutual trust. The operating rules of the entire system are open and transparent, and all data content is also public, so it is within the scope of the rules specified by the system. and within the time range, nodes cannot and cannot deceive other nodes. Collectively maintain: The data blocks in the system are jointly maintained by all nodes with maintenance functions in the entire system, and anyone can participate in these nodes with maintenance functions. Reliable Database: The entire system will be divided into databases so that each participating node can obtain a copy of the complete database. Unless more than 51% of the nodes in the entire system can be controlled at the same time, modifications to the database on a single node are invalid and cannot affect the data content on other nodes. Therefore, the more nodes and stronger computing power participating in the system, the higher the data security in the system. Open Source: Since the operating rules of the entire system must be open and transparent, for the program, the entire system must be open source. Anonymity: Since nodes do not need to trust each other, there is no need to disclose their identities between nodes, and every participating node in the system is anonymous. 3. What is blockchain finance? In 2016, innovators will be innovated. The new round of technological revolution will address the challenge of trust between strangers in the sharing economy while destroying the basis for such platforms to make money. Although the traditional intermediary sharing economy effectively challenges the status quo and has strong innovative attributes, it still adopts a very traditional business model. The most common method of charging commissions on transactions has been used for centuries. Today, technology has made many things possible, but it still cannot completely replace intermediaries. When P2P platforms and other online marketplaces first emerged, there was a lot of talk about disintermediation., a new way to connect people directly through the Internet, bypassing traditional intermediaries. Indeed, even though we have experienced how much more convenient new markets are and the possibilities of transacting with a variety of suppliers, we still rely heavily on intermediaries today. The fact is that today’s biggest new businesses are giant intermediaries, whose scale is beyond imagination, like Alibaba, Amazon, eBay, and Uber. Is there a technological solution that can completely remove the intermediary between transaction parties? Is there a system where you can trade directly with anyone and be safe from being cheated, but no one owns the system so there is no commission taker. Blockchain technology makes this possible. Blockchain is the core technology of Bitcoin. It is extremely innovative and can be used to build a completely transparent, ownerless and decentralized system. It can ensure the safety of various transaction parties without any form of intermediary. These transactions Parties include people and businesses. Naturally, a lot of resources are flowing to blockchain. Blockchain has also brought considerable impact to the financial and legal industries, and will eventually wreak havoc in these two industries, or provide the best opportunities. It all depends on how you look at it. it. Decentralized Finance In 2015, probably out of high sensitivity to the growth of the alternative finance market, nine investment banks jointly developed open standards for blockchain technology financial services. Last year saw constant activity discussing the future of blockchain technology and the launch of Slock.it, one of the first technology stacks for the decentralized sharing economy. What does the sharing economy look like under the blockchain? If you want to continue to earn commissions in the sharing economy, you need to create new business models. Of course, the blockchain market will still require some investment. Developers may be happy to spend time solving code that plagues the system. However, I have yet to meet the overdue branding consultants, designers or businesspeople who have similar ideas or are willing to invest. Code alone cannot help the blockchain market enter the mainstream. But blockchain will flourish, and by getting rid of annoying intermediaries, it will almost certainly become cheaper than the existing sharing economy, and by then the giants will be forced to deal with it. Will the old sharing economy repeat history, decline due to its belief that it is indestructible, and be quickly replaced by competitors that are more flexible and equipped with technology? Or will you experiment, find a profitable market in Sharing Economy 2.0, and beat the game? What about credit? Credit is the most frequent word in all discussions related to the sharing economy, and it is quite complex and tricky. The current collaboration platforms have made it very clear: we can improve the level of trust in the sharing economy; we can take optimal measures to ensure that users trust our platform and transact on it, but we cannot guarantee that transactions between people are trustworthy. The blockchain solution solves the above problems. The transaction system in the blockchain is immutable and each transaction can be tracked within the assigned ledger. Smart contracts fully set parameters and conditions for all bilateral transactions, so the blockchain no longer requires anyA “trusted intermediary” or a guarantor of credit between strangers. By 2017, regulators will realize they need to radically rethink the rules and regulations governing the sharing economy. At that time, each transaction party will reach hundreds of millions of independent contracts in the blockchain. One solution is to type rule code into the system. When the sharing economy first appeared around 2008, many people cheered, believing it to be a phenomenon that would lead us into a new inclusive and sustainable economy, and a democratizing force that would lead us into the post-capital paradigm in the future. However, (so far) this is not the case. The same was true when the Internet first emerged. It was utopian in its initial stages, so people who hold the same transformative expectations for blockchain are likely to be disappointed. Even so, it won’t hurt in the least that blockchain will shake up the giants of the sharing economy. 4. Blockchain community Bubi Blockchain focuses on the innovation of blockchain technology and products. It already possesses a number of core technologies and has developed its own blockchain service platform. With decentralized trust as the core, we are committed to building an open value circulation network to allow digital assets to flow freely. Features and Advantages It has achieved a number of core technological innovations and developed its own basic blockchain service platform, which has been applied in equity, supply chain, points, credit and other fields. Fast transaction verification By optimizing key transaction links such as signature algorithms, consensus mechanisms, and ledger storage, Bubi Blockchain can achieve fast transaction verification in seconds. Efficient Ledger Access Bubi Blockchain’s adjustments to the ledger storage structure can save 90% of storage space and reduce the risk of long-term system operation, resulting in reduced ledger access performance. Multiple asset issuance Bubi blockchain supports the issuance and trading of multiple assets by different users. Each asset can track and record the issuer, issuance quantity, transaction circulation and other details. Joint signature control allows multiple users to be set up under the same account, and corresponding permissions are set for different operations to meet the usage scenarios of multi-party signature control. Built-in smart contract A smart contract is a set of promises defined in digital form. The blockchain becomes a participant in the contract and is responsible for maintaining, saving and automatically executing the contract. Compared with traditional centralized exchanges, on-chain exchanges use blockchain to build a trading platform where all transactions are verified, completed and saved on the chain to ensure user transaction security. What Bubi Blockchain wants to do is to create a new technology and product - to realize real value circulation and bring the Internet to a new level. With the application of this technology, there will be no central organization when transferring assets, and direct transfer of assets between us can be achieved. In the future, if the network itself can checkout, we can transfer directly without going through an intermediary.

『三』What is blockchain and how to introduce blockchain in a simple and easy-to-understand manner

Many people don’t know what blockchain is. Here I will give you a detailed introduction. Blockchain is a new technology that subverts the old model. Just like people tend to ignore the invisible but indispensable oxygen, people often ignore the most important thing in the market economy, which is trust. no trust, anyThe transaction cannot be established.

In addition, different races, nationalities, cultures, religious beliefs, etc. will form a trust gap. Due to the lack of mutual understanding and necessary trust between strangers, it is difficult for transactions to occur. The market economy emerged in large numbers among strangers. The emergence and development of the market economy lies in the birth of a new mechanism, which solves the problem of trust between strangers.

The concept of blockchain was first proposed in a paper written by Bitcoin founder Satoshi Nakamoto in 2008. Blockchain can be understood as a kind of public accounting. Technical solution: All data will be open and transparent, without the need for a central server as a trust intermediary, thus ensuring the authenticity, immutability and credibility of information on a technical level. The immutability of data is very important.

Because the blockchain has the technical characteristics of large-scale expansion, open and transparent data, and because the data of each client is consistent, even if some clients are destroyed, it will not affect the reliability of data security. In particular, it can effectively solve the problem of trust between strangers, so this technology can be extended to all fields that can be digitized, such as digital currency, payment settlement, digital bills, proof of rights, credit information, government services, medical records, etc. If blockchain technology develops, it will be closely related to everyone in the future.

『四』 One article to understand the Internet blockchain

One article to understand the Internet blockchain

One article to understand the Internet blockchain, you need to understand the blocks In order to understand the blockchain, we have to study the brief history of the technological development of the blockchain starting from the birth of the Internet, discover the motivations for the emergence of the blockchain, and infer the future of the blockchain. Let’s understand the Internet blockchain in one article.

Understand the Internet blockchain in one article 1

The originator of blockchain is mahjong, and the earliest blockchain was invented by the Chinese! The blockchain is just like Mahjong, except that Mahjong has fewer blocks. Mahjong only has 136 blocks. The rules of Mahjong vary from place to place and can be regarded as a hard fork of Bitcoin.

As the oldest blockchain project, Mahjong has a team of four miners. The first one to dig out the 13 correct hash values ​​will get the accounting rights and rewards. It adopts the method of being willing to admit defeat and not cheating. Thousands of consensus mechanisms!

Mahjong is decentralized, everyone can be the banker, and it is completely peer-to-peer.

Mining pool = commission from the boss of the chess and card room.

It cannot be tampered with, because convincing the other three people requires too much computing power and physical strength.

A typical value Internet. The value in my pocket didn't last eight rounds before it went into their pockets.

The Chinese are basically good at playing mahjong. In terms of blockchain, they produce 70% to 80% of the world’s mining machines and have the most computing power in the world, accounting for about 77% of the computing power.

Mahjong is actually the earliest blockchain project:

1. A group of four miners collide to get the correct hash value of 13 numbers.Miners can obtain accounting rights and receive rewards.

2. It cannot be tampered with. Because convincing the other three people requires too much computing power and physical strength.

3. Typical value Internet. The valuable digital currency www.gendan5.com/digitalcurrency/btc.html in my pocket ran into their pockets after eight rounds.

4. Decentralization, everyone can be a banker, it is completely peer-to-peer.

5. UTXO, unspent transaction expenses.

There is another blockchain method of credit, assuming that everyone has no cash

Let’s take a closer look. When everyone reaches a consensus, we see There is no intermediary or third party to judge C’s win, and the rewards given to C do not need to be transferred to C through a third party. They are all direct peer-to-peer transactions. This process is decentralized, and players (miners) record their own records. After recording the results of the first game, B Dahu drew thirteen pieces, and B got Jia Dongfeng. After the record was completed, a complete block was generated, but remember, this was only the first game. In the entire blockchain , this is just one node. After the 8 rounds mentioned at the beginning, there are 8 nodes (blocks). The 8 blocks are connected together to form a complete ledger, which is the blockchain. Because everyone has one of this ledger, it is a distributed ledger. The purpose is to prevent someone from tampering with the record. At the end of the game, it is clear who wins and who loses.

Four men (A, B, C, and D) got together to play mahjong for money. None of them brought any cash, so they asked a beautiful woman (centralized) to keep a book and record who won how much money in each round. , Who lost how much? At the end of the day, everyone uses Alipay or WeChat to pay and settle the ledger. However, if this beauty made a mistake in accounting or was bribed by one of the four people in advance to make a mistake on purpose, there is no guarantee that the outcome of this game will be fair, just, and reasonable. ,dont you agree? then what should we do? If you "play mahjong", you can use "blockchain" as the game rules and adapt it as follows:

Four men (A, B, C and D) got together to play mahjong for money. No one brought any cash. B said Let the beauty she brought keep accounts. A said that none of us knew this beauty, so the four of them, A, B, C, and D, agreed that everyone would keep accounts at the same time (decentralized) on their mobile phones (blockchain nodes) for each game. ), after finally playing mahjong and paying with electronic money directly on the mobile phone, everyone checked the accounting results. The accounting results should have been the same.

Assume that the original result is the account recorded on A’s mobile phone: B owes A 10 yuan. However, the record on B's mobile phone shows that there is no debt, but the other two people (C and D) have the same accounting as A, so the settlement is still based on the majority rule. In addition, everyone has a bad impression of B's ​​integrity. Next The first time I play mahjong, I won’t take B to play with me.

Unless B bribes 2 people (C and D) in advance to intentionally cheat, but B bribes 2 of themThe price of a person is 100,000 yuan (10,000 times the 10 yuan for defaulting on a debt), so logically speaking, B can only choose to give up because the cost of fraud is too high.

Assume that even if B is secretly willing to pay a high price of 100,000 yuan to buy C and D to do this silly cat transaction with huge losses during the card game, the rules of the blockchain are to keep accounts based on timestamps. Yes, it turns out that B owed A 10 yuan when debiting the account at 1 p.m., that is, when C and D changed the account at 3 p.m., time is irreversible and they can only record 3 p.m., which does not comply with the rules of the game. .

In fact, in 2017 the blogger has developed a set of Mahjong coins

China’s earliest blockchain project: a group of four miners, first starting from 148 random numbers The miner who collides with the correct hash value of 14 numbers can obtain an accounting right incentive. Since distributed accounting requires the consensus of several other miners, each accounting transaction takes about ten minutes.

Understanding the Internet Blockchain in One Article 2

1. Before the birth of Bitcoin, 5 Internet technologies that will have a significant impact on the future of the blockchain

In 1969, the Internet was born in the United States. Since then, the Internet has expanded from four research institutions in the United States to the entire planet. In terms of application, it has expanded from the earliest military and scientific research to all aspects of human life. In the nearly 50 years since the birth of the Internet, five technologies have been of particularly great significance to the future development of blockchain.

1. The TCP/IP protocol born in 1974: determines the position of blockchain in the Internet technology ecosystem

In 1974, the most critical step in the development of the Internet was taken by The TCP/IP protocol, the core communication technology of the Internet jointly developed by American scientists Vinton Cerf and Robert Kahn, was officially launched.

This protocol enables the transmission of information between different computers and even different types of networks. All computers connected to the network can communicate and interact as long as they comply with this protocol.

In layman's terms, Internet data can travel tens of thousands of kilometers to reach the computer users who need it. This is mainly because the Internet world has formed a unified information dissemination mechanism. That is to say, Internet devices follow a unified law-TCP/IP protocol when disseminating information.

Understanding the TCP/IP protocol is of great significance to mastering the Internet and blockchain. After the invention of TCP/IP in 1974, the entire Internet was between the underlying hardware devices, the intermediate network protocols and the network Addresses have always been relatively stable, but an endless stream of innovative applications are emerging at the top application layer, including news, e-commerce, social networks, QQ, WeChat, and blockchain technology.

In other words, in the technical ecology of the Internet, blockchain is a new technology at the top layer of the Internet - the application layer. Its emergence, operation and development have not affected the underlying infrastructure and communication protocols of the Internet. , still runs according to the TCP/IP protocolOne of many software technologies.

2. Cisco router technology born in 1984: an imitation of blockchain technology

In December 1984, Cisco was established in the United States. The founder was a professor from Stanford University. A couple, Leonard Posak, director of the computer center, and Sandy Lerner, director of the business school's computer center, designed a networking device called a "multiprotocol router" that was placed on the Internet's communication lines to help data Get from one end of the Internet to the other thousands of kilometers away accurately and quickly.

In the entire Internet hardware layer, tens of millions of routers are busy working, directing the transmission of Internet information. An important function of Cisco routers is that each router saves a complete Internet device address table. Once something happens Changes will be synchronized to tens of millions of other routers (theoretically), ensuring that each router can calculate the shortest and fastest path.

When you see the operation process of the router, you will feel very familiar. That is the important feature of the blockchain later. The significance of understanding the router lies in the important features of the blockchain. It has been implemented on the router in 1984. For the router, even if the node device is damaged or attacked by hackers, it will not affect the transmission of the entire Internet information.

3. The B/S (C/S) architecture that was born with the World Wide Web: the opponent of the blockchain and the target of attempted subversion

The World Wide Web is referred to as the Web and is divided into Web clients and server. All updated information is only modified on the Web server. Thousands, tens of thousands, or even tens of millions of other client computers do not retain the information and only obtain the information data when accessing the server. This structure is often called the Internet B/S architecture is a centralized architecture. This architecture is also the most important architecture of the current Internet. Internet giants such as Google, Facebook, Tencent, Alibaba, and Amazon have all adopted this architecture.

Understanding the B/S architecture will be of great significance to the subsequent understanding of blockchain technology. The B/S architecture is that data is only stored in the central server, and all other computers obtain information from the server. Blockchain technology has tens of millions of computers without a center, and all data will be synchronized to all computers. This is the core of blockchain technology.

4. Peer-to-Peer Network (P2P): Blockchain The father of the chain and its technical basis

Peer-to-peer network P2P is another Internet infrastructure corresponding to C/S (B/S). Its characteristic is that multiple computers connected to each other are connected to each other. In a peer-to-peer position, there is no distinction between master and slave. A computer can be used as a server, setting shared resources for use by other computers in the network, and as a workstation.

Napster is one of the earliest P2P systems, mainly used for music resource sharing. Napster cannot be regarded as a true peer-to-peer network system. 2000 3On March 14, a message was posted on the Slashdot mailing list of the US underground hacker site, saying that AOL's Nullsoft department had released Gnutella, an open source Napster clone software.

In the Gnutella distributed peer-to-peer network model, each networked computer is functionally peer, serving as both a client and a server, so Gnutella is called the first true peer-to-peer network model. Network Architecture.

In the past 20 years, some Internet technology giants such as Microsoft and IBM, as well as liberals, hackers, and even criminals who infringe intellectual property rights, have continued to promote the development of peer-to-peer networks. Of course, those on the Internet want to strengthen information sharing. The idealists also put a lot of enthusiasm into peer-to-peer networks. Blockchain is a software application based on a peer-to-peer network architecture. It is a benchmark application for peer-to-peer networks trying to break out from the silence of the past.

5. Hash algorithm: the key to generating Bitcoin and tokens (tokens)

The hash algorithm converts numbers of any length into fixed-length values ​​using a hash function. Algorithms, famous hash functions such as: MD4, MD5, SHS, etc. It is a member of the family of cryptographic functions defined by the American National Institute of Standards and Technology.

This family of algorithms is crucial to the functioning of the entire world. From Internet application stores, emails, anti-virus software, to browsers, etc., all of them are using secure hashing algorithms. It can determine whether Internet users have downloaded what they want, and it can also determine whether Internet users are involved in man-in-the-middle attacks or network attacks. Victim of a phishing attack.

The process of blockchain and its application to generate new coins from Bitcoin or other virtual currencies is to use the function of the hash algorithm to perform operations to obtain numbers that meet the format requirements, and then the blockchain program gives Bitcoin rewards.

Mining, including Bitcoin and tokens, is actually a small mathematical game built with a hash algorithm. However, because of the fierce competition, people all over the world used powerful servers to perform calculations in order to get the rewards first. As a result, many computers on the Internet participated in this little mathematical game, which even consumed more than 40% of the electricity in some countries.

2. The birth and technical core of blockchain

The birth of blockchain should be the most unusual and mysterious invention and technology in the history of human science, because apart from blockchain, So far, there is no major invention in the history of modern science whose inventor cannot be found.

On October 31, 2008, Bitcoin founder Satoshi Nakamoto (pseudonym) published a paper on the cryptography mailing group - "Bitcoin: A Peer-to-Peer Electronic Cash System". In this paper, the author claims to have invented a new electronic currency system that is not controlled by governments or institutions. Blockchain technology is the basis for supporting the operation of Bitcoin.

The preprint address of the paper is at http://www.bitcoin.org/bitcoin.pdf, from an academic point of view, this paper is far from a qualified paper. The main body of the article is composed of 8 flow charts and corresponding explanatory text. There are no defined nouns and terms, and the paper format is also very irregular.

In January 2009, Satoshi Nakamoto released an application case of blockchain on the SourceForge website - the open source software of the Bitcoin system. After the release of the open source software, it is said that Satoshi Nakamoto mined approximately 1 million bits. Coin. A week later, Satoshi Nakamoto sent 10 Bitcoins to cryptography expert Hal Finney, which became the first transaction in Bitcoin history. With the booming development of Bitcoin, research on blockchain technology has also begun to show explosive growth.

It is indeed difficult to fully and clearly explain the blockchain to the public. We use Bitcoin as the object to introduce the technical characteristics of the blockchain as simply as possible but in depth.

1. Blockchain is a peer-to-peer network (P2P) software application

As we mentioned before, at the beginning of the 21st century, the Internet formed two major types of applications. Architecture, centralized B/S architecture and non-centered peer-to-peer (P2P) architecture. Many Internet giants such as Alibaba, Sina, Amazon, etc. all have centralized B/S architecture. Simply put, it is data Put it in a giant server, and our ordinary users can access the servers of Alibaba, Sina and other websites through mobile phones and personal computers.

Since the beginning of the 21st century, there have been many software applications for freely sharing music, videos, and paper materials. Most of them use a peer-to-peer network (P2P) architecture, that is, there is no central server, everyone's personal computer They are all servers and clients, with equal status. However, this type of application has never become popular. The main reasons are large resource consumption and intellectual copyright issues. Blockchain is a software application in this field.

2. Blockchain is a peer-to-peer network (P2P) software application that synchronizes information across the entire network

Peer-to-peer networks also have many application methods. In many cases, everyone is not required to Each computer keeps the same information. Everyone only stores the information they need, and downloads it to other computers when needed.

However, in order to support Bitcoin financial transactions, the blockchain requires that every transaction that occurs must be written into historical transaction records and change information be sent to all computers with Bitcoin programs installed. Every computer with Bitcoin software installed maintains the latest and complete Bitcoin historical transaction information.

The characteristics of blockchain's network-wide synchronization and network-wide backup are often referred to as blockchain information security, and the source cannot be changed. Although it is still not absolutely safe in practice, when the number of users is very large, it does have certain security advantages in preventing information tampering.

3. Blockchain is a synchronization of information across the entire network that uses a hash algorithm to generate "tokens"Waiting for network (P2P) software applications

The first application of blockchain is the famous Bitcoin. When discussing Bitcoin, a term often mentioned is "mining", so mining what is it?

The metaphor is that the blockchain program gives the miners (players) 256 coins, numbered 1, 2, 3...256. Each time a Hash operation is performed, it is like tossing a coin. 256 coins are thrown at the same time. After landing, if all the coins with the first 70 numbers happen to be heads. The miner can tell the blockchain program this number, and the blockchain will reward the miner with 50 Bitcoins.

From the perspective of software programs, Bitcoin mining is a mathematical game built using the hash SHA256 function. The blockchain first stipulates a winning mode in this small game: a 256-bit hash number is given, but the last 70 bits of the hash number are all 0, and then the player (miner) continuously enters various numbers. Give the hash SHA256 function and see if you can use this function to get a number with 70 zeros. If you find one, the blockchain program will reward the player with 50 Bitcoins. Actual mining and rewards are more complex, but the above example expresses the core process of mining and obtaining Bitcoin.

When Bitcoin was born in 2009, each bounty was 50 Bitcoins. Ten minutes after its birth, the first batch of 50 Bitcoins was generated, and the total currency amount at this time was 50. Subsequently, Bitcoin increased at a rate of about 50 every 10 minutes. When the total amount reaches 10.5 million (50% of 21 million), the bounty is halved to 25. When the total amount reaches 15.75 million (new output is 5.25 million, which is 50% of 1050), the bounty is further halved to 12.5. According to the design of the Bitcoin program, the total number of Bitcoins is 21 million.

From the above introduction, Bitcoin can be seen as a guessing game based on a peer-to-peer network architecture. The Bitcoin information rewarded for each correct guess will be transmitted to all players and recorded. into each player's history database.

4. Smart contracts, tokens, ICOs and blockchain basic platforms generated by blockchain technology due to the rise of Bitcoin

From the above introduction, Bitcoin technology It is not a new technology falling from the sky, but a clever combination of various original Internet technologies, such as peer-to-peer network architecture, network-wide synchronization of routing, and network security encryption technology. It can be regarded as a combination of innovative algorithm games. .

Because Bitcoin can be exchanged for legal currency, purchased in kind, and made huge profits through appreciation, the whole world is not calm. With the attitude that if you can do it, I can do it, many people have created their own imitation Bitcoin software applications. At the same time, taking advantage of the difficulty for the government to regulate peer-to-peer networks, various altcoins exploded together with Bitcoin. There have been many incidents of fraud and absconding, which have gradually attracted the attention of governments around the world.

Blockchain BasicsTaiwan: It is still quite technically difficult to create currency using the blockchain technology framework. At this time, basic technology platforms such as Ethereum, the basic blockchain platform, have emerged, allowing ordinary people to easily create "Bitcoin"-like software programs, each showing Magical power, invite people to join the game to mine coins, speculate in coins, and gain profits from it.

Pass or token: If each "Bitcoin" or "Altcoin" uses a hash algorithm to create a guessing game and generates its own "currency", this "currency" is collectively referred to as " "Certificate" or "Token".

ICO: Since Bitcoin and Ethereum have been exchanged with the legal currencies of various countries, when other new virtual currencies are issued, only Bitcoin and Ethereum are allowed to purchase the new issued coins. This process of issuing coins It’s called ICO. The emergence of ICO has amplified the transaction volume of Bitcoin and Ethereum. At the same time, many ICO projects are completely based on nihilistic projects, resulting in a large number of frequent fraud cases. This further deepens society’s negative understanding of virtual currencies generated by blockchain.

Smart contract: It can be seen as a software function on the blockchain. It is a program that assists various virtual currency transactions on the blockchain. The specific function is like the fund custody of Alipay on Taobao. When a user receives goods and confirms them on Alipay, the funds are automatically paid to the buyer and owner. Smart contracts also assume this intermediary payment function in blockchain applications such as Bitcoin.

3. The historical status and future prospects of blockchain technology in the Internet

1. Where does blockchain stand in Internet technology? It is a new software and architecture at the top level.

We mentioned in the previous introduction to TCP/IP that blockchain, like browsers, QQ, WeChat, online game software, mobile APPs, etc., is a software form of the top layer of the Internet - the application layer. . Its operation still relies on the TCP/IP architecture system to transmit data. But unlike most application layer software, it does not adopt the central software architecture of C/S (B/S). Instead, an unusual peer-to-peer network architecture is adopted. From this point of view, blockchain cannot subvert the Internet infrastructure.

2. Who does blockchain want to subvert? Want to subvert the B/S (C/S) structure of the World Wide Web.

It attempts to subvert the B/S, C/S structure of the World Wide Web, which was born in 1989. Said before. Since 1989, European physicist Tim Berners-Lee invented the World Wide Web and gave up applying for a patent. In the past nearly 30 years, companies including Google, Amazon, Facebook, Alibaba, Internet, Tencent and other companies have used the B/S (C/S) structure of the World Wide Web to grow into Internet giants.

In their headquarters, a powerful central server cluster was established to store massive amounts of data. Hundreds of millions of users obtained the data they needed from the giant servers. This also led to the emergence of cloud computing, and then the Internet giants Open up your unused central server resources to further absorb data from enterprises, governments, and individuals.Centralized Internet giants have an increasing influence on the world, countries, and Internet users.

The goal of blockchain is to try to reduce the influence of Internet giants by distributing data to each Internet user’s computer. It can be seen that the real opponent of blockchain and what it wants to subvert is the 1990 The B/S (C/S) structure born in 2007. But whether it can be subverted depends on its technical advantages and bottlenecks.

3. Technical flaws of blockchain: dilemmas caused by the pursuit of complete equality and freedom

The technical flaws of blockchain first come from its peer-to-peer network architecture. For example For example, Taobao currently has a B/S structure, and massive data is stored in the Taobao server cluster computer room. Hundreds of millions of consumers access the Taobao server website through their browsers to obtain the latest information and historical information.

If blockchain technology is used, hundreds of millions of people will retain a complete Taobao database on their personal computers or mobile phones. Every time a transaction occurs, it will be synchronized to hundreds of millions of other users. This is completely unachievable in reality. The amount of data transferred and stored is too large. It is equivalent to setting up and running hundreds of millions of Taobao websites at the same time.

Therefore, blockchain cannot be applied to projects with large amounts of data, and even smaller website projects will have difficulty using blockchain. By 2018, Bitcoin had been running for nearly 10 years, and the accumulated transaction data had brought the entire system to collapse.

So the blockchain has adopted many alternative methods, such as establishing relay nodes and lightning nodes. These two concepts can also make people confused. In layman’s terms, the blockchain will ask it for The subversive object B/S structure has been studied, and a data server center has been established to become the relay node of the blockchain, which can also be accessed with a browser-like terminal. This is the lightning node of the blockchain.

This change can alleviate the technical shortcomings of the blockchain, but it does make the blockchain what it opposes, centralization. It can be seen that pure blockchain technology has major flaws due to its technical characteristics and cannot be widely used like the World Wide Web. If the technology is upgraded and some parts adopt a B/S (C/S) structure, the blockchain will become centralized. The information node no longer maintains the dream when it was born.

4. Looking at the future prospects of blockchain from the Internet brain model

We know that the Internet generally refers to the Internet that connects computer networks around the world. On this basis The development of a global Internet network covering the whole world is called the Internet, which is a network structure that is interconnected.

Since the birth of the Internet in 1969, humans have innovated in the Internet field from different directions, and there is no unified plan to build the Internet into a structure. When the wheel of time reaches 2017, with the advent of artificial intelligence, With the vigorous development of science and technology such as the Internet of Things, big data, cloud computing, robots, virtual reality, and the industrial Internet, when humans look up to see the giant systems they have created, the model and architecture of the Internet brain have become increasingly clear.

Through nearly 20 years of development, relying on the B/S and C/S structures of the World Wide Web, Tencent QQ, WeChat, Facebook, Weibo, and Twitter Amazon have developed structures similar to neuron networks. Internet devices, especially personal computers and mobile phones, map personal data and functional space on the giant's central server through the software on the device, allowing them to add friends, communicate and transfer information. Internet giants continue to optimize the software versions of hundreds of millions of terminals through software upgrades in central server clusters. In the neurological system, this is a standard central nervous system structure.

The birth of the blockchain provides another neuron model. Instead of uniformly managing neurons in the centralized services of giants, each terminal, including personal computers and personal mobile phones, becomes an independent neuron node. , retaining an independent data space and synchronizing mutual information. In the neurological system, this is a distributed neural structure with no center and multiple neural nodes.

Interestingly, these two different types of neural structures appear in the development of the nervous system. In lower organisms, blockchain-like neural structures have appeared. There are multiple ganglia with the same functions, all of which can command body activities and reactions. However, as organisms evolve, these ganglia gradually merge. When they evolve into higher In biology, the central nervous system appeared, which contains a large number of neurons that interact with each other.

4. Judgment on the future status of blockchain in the Internet

1. Understanding of Bitcoin: a guessing game based on peer-to-peer network architecture (P2P), Through clever financial and public opinion operations, it has become a "world currency" that is not subject to government supervision.

2. Understanding of blockchain: a peer-to-peer (P2P) software application that uses hashing algorithms to generate "tokens" to synchronize information across the entire network.

3. Blockchain has specific uses, such as large-scale election voting, large-scale gambling, financial transactions that circumvent government financial supervision, etc. It still has irreplaceable uses.

4. In more cases, blockchain technology will rely on the B/S and C/S structures of the Internet to achieve functional expansion, but overall it is still a supplement to the existing technology of the Internet. Most of the application scenarios currently envisaged by blockchain can be implemented using B/S and C/S structures, with higher efficiency and more mature technology.

5. Whether from the perspective of information transmission efficiency and resource consumption, or from the evolution of the nervous system, blockchain cannot become the mainstream architecture of the Internet, let alone a subversive and revolutionary leader of the future Internet.

6. Of course, Internet giants developed with B/S and C/S structures also have their problems, but these can be gradually solved through commercial and political methods in the future.

『五』A paper on the prospect of blockchain in the financial field

A paper on the prospect of blockchain in the financial field

Blockchain technology was born in 2008, and its first application was Bitcoin. Blockchain technology uses a decentralized consensus mechanism to maintain a complete, distributed, and non-tamperable ledger database, allowing participants in the blockchain to implement a unified ledger system without establishing a trust relationship. . In 2015, many mainstream financial institutions in Europe and the United States recognized the application prospects of this technology and explored the application of blockchain technology in the financial field. The International Monetary Fund pointed out in a report that "it has the potential to change finance." Some people believe that blockchain technology will change human society as profoundly as double-entry accounting and shareholding.

Blockchain will make it possible for all individuals to become important nodes in the allocation of financial resources. It will also promote the improvement of the existing financial system and financial rules, and build a shared and win-win situation. type of financial development ecosystem. The emergence of blockchain technology is a revolution in human credit creation. It allows both parties to the transaction to carry out economic activities without the need for third-party credit intermediaries, thereby achieving low-cost value transfer. It can be said that blockchain technology is a more efficient value exchange technology in the Internet era. The Internet has evolved from an information Internet that transmits information to a value Internet that transfers value. This is conducive to traditional financial institutions taking advantage of the opportunity to transform and transform endogenous businesses. Processes and application scenarios are Internetized.

1. Characteristics and shortcomings of blockchain

(1) Main characteristics of blockchain

(1) Decentralization. In the blockchain, there is no centralized hardware or management organization. The distributed structure system and open source protocol allow all participants to participate in the recording and verification of data, which is then sent to various nodes through distributed propagation. Each participant The nodes are all "self-centered", and the rights and obligations are equal. Blockchain is not simply decentralized, but multi-centered or weakly centered. When the Internet of Things makes it possible for all individuals to become central nodes, the central status of traditional financial intermediaries changes, transforming from a monopoly-type, resource-advantaged center and strong intermediary to an open platform, becoming a service-oriented multi-center. Center of differentiation.

(2) To trust. From a trust perspective, blockchain uses a set of open and transparent mathematical algorithms based on consensus specifications and protocols to enable all nodes to automatically and securely exchange data in a trustless environment. Blockchain essentially solves the problem of trust through mathematical methods. All rules are expressed in the form of algorithmic programs. Participants do not need to know the credit level of the counterparty, and do not need transaction endorsement or guarantee verification from a third-party institution. They only need trust. A common algorithm creates credit, generates trust, and reaches consensus for participants through the algorithm.

(3) Timestamp. Blocks are generated by packaging data and code within a period of time. The header of the next block contains the index information of the previous block, and a chain is formed by connecting the end to the end. Blocks that record complete history and chains that can be fully verified form a traceableThe timestamp of the complete history can provide retrieval and search functions for each piece of data, and can be traced back to the source and verified piece by piece with the help of the blockchain structure. Therefore, the blockchain is timestamped when generated, forming a database that cannot be tampered with or forged. Modifications to the database on a single node are invalid unless more than 51% of the nodes in the system can be controlled at the same time, so the data reliability of the blockchain is very high.

(4) Asymmetric encryption. Blockchain uses an asymmetric encryption algorithm, that is, a "key pair" is used in the encryption and decryption process. The two keys in the "key pair" have asymmetric characteristics. In the application scenario of blockchain, on the one hand, the key is the public key visible to all participants. Participants can use the public key to encrypt a piece of authenticity information, and only the owner of the information can use the private key to decrypt it. On the other hand, the private key is used to sign the information, and the signature is verified by the corresponding public key to ensure that the information was sent by the real holder. Asymmetric encryption minimizes friction boundaries in value exchange, enables transparent data anonymity, and protects personal privacy.

(5) Smart contract: Since the blockchain can realize point-to-point value transfer, corresponding programming scripts can be embedded during transfer. This smart contract method is used to handle some unforeseen transaction patterns and ensure Blockchain can continue to be effective. This kind of programmable script is essentially a list of many instructions to achieve pertinence and conditionality in value exchange and to achieve specific uses of value. Therefore, any value exchange activity based on the blockchain can achieve hard control over its use, direction and various restrictions through intelligent programming, eliminating the cost of soft constraints by law or contract.

(2) Main problems of blockchain

(1) High energy consumption problem. There is an impossible triangle in the traditional currency and banking system, that is, it is impossible to achieve decentralization, low energy consumption and high security at the same time. The impossible triangle also exists in the construction of blockchain. For example, in the actual application of Bitcoin, its development has brought about the rapid expansion of computer hardware, and the main costs in the "mining" process have shifted to hardware costs and electricity costs. Therefore, after applying blockchain technology to achieve equity cost benefits, maximizing its technical efficacy has become an urgent problem to be solved.

(2) Storage space problem. Since the blockchain records every transaction information from the initial information in the system, and each node has to download, store and update data blocks in real time, if the data of each node is completely synchronized, the network pressure will be great, and each node will The storage space capacity requirements of each node may become a key issue restricting its development.

(3) The problem of stress resistance. The system built based on the blockchain follows the barrel theory and must take into account the worst processing speed and network environment among all network nodes. Therefore, if the blockchain technology is promoted to a large-scale transaction environment, its overall stress resistance It remains to be verified. If the transaction volume generated per second exceeds the design capacity of the system (the weakest node), the transaction will automatically enter the queue for processing.Queuing creates a bad user experience.

2. Application of blockchain in the financial field

(1) Financial infrastructure

Blockchain may be used as the infrastructure of the Internet in many fields. All show broad application prospects. In the financial industry, blockchain technology will first affect financial infrastructure such as payment systems, securities settlement systems, and transaction databases. Later, the technology will also expand to general financial services, such as credit systems, "anti-money laundering," etc. This is because, based on the characteristics of blockchain technology, it will first enter the infrastructure field with high trust requirements and high cost of traditional trust mechanisms. In the past, infrastructure was a public product, but new technologies and new systems of blockchain have made it more It is possible for multiple people to participate in the provision of public goods. The future of Internet finance will use Internet technologies such as blockchain to transform the core production systems of traditional financial institutions and build financial enterprises on the Internet.

The current information Internet can be collectively referred to as the TCP/IP model, and HTTP is the most important application protocol in the application layer. In the Internet of Value, blockchain is a point-to-point transmission protocol in the application layer. Its value is the same as that of the HTTP protocol in the information Internet. The huge potential and prospect of blockchain is that it can reconstruct the infrastructure and core production systems of the traditional financial industry, not just at the application level such as APPs. This is because, at the network level, the blockchain is based on the IP communication protocol and the distributed network; at the data level, the blockchain database system is brand new and is significantly better than the existing one. There is a database of the financial system; at the application level, registration and settlement, clearing systems, smart contracts, and the Internet of Things based on the blockchain can greatly improve efficiency. Financial activities on the blockchain are programmable finance. .

(2) Digital Currency

From the perspectives of security and cost, it is a general trend that banknotes will be replaced by new technologies and new products. The establishment of digital currency issuance and circulation systems is very necessary for financial infrastructure construction and economic development. Following the integration of traditional currency and digital currency, the issuance, circulation and trading of digital currency should be led by the central bank, reflecting convenience and security, and achieving a balance between protecting privacy, maintaining social order, and combating illegal and criminal activities. It is conducive to the effective operation and transmission of monetary policy. It is necessary to retain the control of monetary sovereignty. Digital currency is freely convertible and controllable.

The success of blockchain technology on Bitcoin proves the feasibility of programmable digital currency. Research from the Bank of England suggests that central banks could consider issuing blockchain-based digital currencies, which could increase financial stability. The technical routes of digital currency can be divided into two types: account-based and non-account-based. They can also be used in layers to try to coexist. The characteristic of blockchain technology is distributed bookkeeping, which is not account-based and cannot be tampered with. If the digital currency focuses on protecting personal privacy, this technology can be used. However, currently blockchain occupiesThere are too many computing resources and storage resources to cope with the current transaction scale. This problem needs to be solved before it can be promoted and applied.

(3) Self-finance

From the perspective of services and non-monetary creation, modern finance is realized through intermediaries. In the Internet era, it is possible to achieve direct finance in the true sense of disintermediation. However, this possibility is not complete. The main reason is that the current Internet finance is based on the original finance and cannot be jumped out. Blockchain technology provides a possibility. Blockchain can be divided into public blockchain and private blockchain. Public blockchains are like Bitcoin. Once the protocol is approved, it becomes an integral part of the blockchain. Private blockchains still need to be permissioned, and blockchain technology in banking systems requires auditing of each participant. Private blockchain is very similar to a form of self-finance, and public blockchain is more similar to the support and guarantee for the bottom layer of private blockchain. When blockchain technology is widely used and third-party financial management technology is generally available, self-financing based on blockchain technology will become completely possible.

3. Blockchain Application and Financial Supervision

Blockchain technology is currently the only tool that can be used to record and prove transaction consistency and company financial accuracy without the need for a third party. Therefore, it can meet the requirements of potential regulators and the public for audit effectiveness, accuracy and timeliness, and has broad application prospects in the financial field. However, its development is still restricted by the current system. On the one hand, blockchain has had an impact on the current system because its decentralized and autonomous characteristics dilute concepts such as the state and supervision. For example, digital currencies represented by Bitcoin challenge the country's right to issue currency and regulate monetary policy, causing monetary authorities to take a conservative attitude towards the development of digital currencies. On the other hand, regulatory authorities also lack full understanding and expectations of this new technology, and the establishment of laws and systems will be seriously delayed, resulting in the lack of necessary institutional norms and legal protection for blockchain applications, increasing the risks for market entities.

Once blockchain financial technology is widely deployed in the financial industry, the de-financial nature of supervision will occur, and supervisory functions, supervisory methods and supervisory means will be redefined. For example, if securities lending, repurchases, and margin trading can be traded through the blockchain, regulatory authorities can consider using the information from this public ledger to monitor systemic risks in the market, which is not only efficient but also reliable. From a macro-financial perspective, after the emergence of the financial era, the currency creation and transmission mechanism and the credit creation pattern will change. From a micro-finance perspective, with the further development of blockchain technology, finance and business have become difficult to distinguish, and will transcend the meaning of separate and mixed industry supervision. The reform of the financial supervision system needs to be discussed from this perspective.

The "decentralization" brought about by blockchain technology still requires centralized departments to provide regulatory and guarantee support. Regulators can proactively embrace new technologies in Internet finance, U.S. Securities and Exchange Commission Commissioner Kara Stein believes that regulators need to be in a leading position to leverage the strengths of blockchain technology and respond quickly to its potential weaknesses. For example, blockchain technology hopes to break privileges and human manipulation and allow computer algorithms to achieve "free credit notarization." But in practice, due to the lack of supervision, digital currency transactions such as Bitcoin face high risks of speculation and money laundering. Therefore, the application of blockchain technology requires regulatory authorities to formulate relevant standards and specifications to ensure that financial innovative products are used appropriately. At the same time, it is necessary to improve the protection of consumer rights and interests, strengthen education on the protection of financial consumer rights and interests, and improve consumers' awareness of risk prevention.

;

『Lu』 Intensive reading of the blockchain paper——Pixel: Multi-signatures for Consensus

The paper mainly proposes a multi-signature algorithm Pixel for the consensus mechanism PoS.

All PoS-based blockchains as well as allowed blockchains have a common structure where nodes run a consensus sub-protocol to reach consensus on the next block to be added to the ledger. Such consensus protocols typically require nodes to check blocking proposals and express their agreement by digitally signing acceptable proposals. When a node sees enough signatures from other nodes on a specific block, it appends them to its view of the ledger.

Since consensus protocols typically involve thousands of nodes working together to reach consensus, the efficiency of the signature scheme is crucial. Furthermore, in order for outsiders to effectively verify the validity of the chain, signatures should be compact for transmission and should be verified quickly. Multisigs have been found to be particularly useful for this task because they enable many signers to create compact and efficient verifiable signatures on public messages.

Additional knowledge: Multi-signature
is a digital signature. In digital signature applications, multiple users are sometimes required to sign and certify the same file. For example, if a statement issued by a company involves the finance department, development department, sales department, after-sales service department and other departments, and needs to be signed and approved by these departments, then these departments need to sign the statement document. A digital signature scheme that enables multiple users to sign the same file is called a multi-digital signature scheme.
Multi-signature is an upgrade of digital signatures, which makes it possible to apply blockchain-related technologies to all walks of life. In actual operation, a multi-signature address can be associated with n private keys. When operations such as transfers are required, funds can be transferred as long as m private keys are signed, where m must be less than or equal to n, that is to say m/n is less than 1, it can be 2/3, 3/5, etc., which must be determined when establishing this multi-signature address.

This article proposes the Pixel signature scheme, a pairing-based forward secure multi-signature scheme that can be used in PoS-based blockchains and can significantly save bandwidth and storage requirements.To support a total of T time periods and a committee of size N, multisig contains only two group elements, and verification requires only three pairings, one exponentiation and N -1 multiplications. Pixel signatures are almost as effective as BLS multi-signatures and also satisfy forward security. Additionally, just like in BLS multi-signatures, anyone can non-interactively aggregate individual signatures into a multi-signature.

Benefit:
To validate Pixel's design, the performance of Pixel's Rust implementation was compared with previous tree-based forward security solutions. Shows how to integrate Pixel into any PoS blockchain. Next, Pixel is evaluated on the Algorand blockchain, showing that it yields significant savings in storage, bandwidth, and block verification time. Our experimental results show that Pixel is effective as a stand-alone primitive and used in blockchains. For example, compared to a set of N = 1500 tree-based forward security signatures (for T = 232) with a 128-bit security level, a single Pixel signature that can authenticate the entire set is 2667 times smaller and can be verified 40 times faster . Pixel signing reduces the size of Algorand blocks of 1500 transactions by approximately 35% and reduces block verification time by approximately 38%.

The biggest difference compared to the traditional BLS multi-signature scheme is that BLS does not have forward security.

Compared with the tree-based forward security signature, the tree-based forward security signature can meet the security requirements, but the signature it constructs is too large and the verification speed needs to be improved. The design of this article reduces the signature size and verification time.

Supplementary knowledge: Forward security
is a security property of communication protocols in cryptography, which means that the leakage of a long-term master key will not lead to the leakage of past session keys. Forward security protects past communications from future exposure of passwords or keys. If a system has forward security, historical communications can be kept safe if the master key is compromised, even if the system is under active attack.

Build forward-secure signatures with Hierarchical Identity Based Encryption (HIBE) and add the ability to securely aggregate signatures on the same message and generate public parameters without a trusted set. To achieve:
1. Generate and update keys
2. Security against malicious key attacks
3. Invalid trust settings

For common post-attacks There are two variants:
1. Short-range variant: The adversary attempts to undermine committee members before a consensus agreement is reached. Resolution: Address short-range attacks by assuming the attack latency is longer than the running time of the consensus subprotocol.
2. Remote variant: solved by fork selection rules.
Forward security signatures provide protection for both attacksA clean solution is provided without the need for fork-choice rules or other assumptions about adversaries and customers. (Explain the advantages of forward secure signatures).

Permissioned blockchain consensus protocols (such as PBFT) are also at the core of many permissioned chains (such as Hyperledger), where only approved parties can join the network. Our signature scheme can be similarly applied to this setting to achieve forward secrecy, reduce communication bandwidth and generate compact block certificates.

In the traditional Bellare-Miner model, the forward security signature scheme FS of the message space M consists of the following algorithms:
1. Setup
pp ←Setup(T), pp is the parties Common parameters that are agreed upon by all, Setup(T) represents the distribution setting of fixed parameters within the T time period.

2. Key generation
(pk,sk1) ←Kg
The signer runs the key generation algorithm on the input maximum time period T to generate public verification for the first time period Key pk and initial secret signing key sk1.

3. Key update
skt+1←Upd(skt) The signer uses the key update algorithm to update the secret key skt of time period t to skt + 1 of the next period. This scheme can also provide a "fast-forward" update algorithm skt0←$Upd0(skt,t0) for any t0 > t, which is more efficient than repeatedly applying Upd.

4. Signing
σ ←Sign(skt,M), when inputting the current signature key skt message m∈M, the signer uses this algorithm to calculate the signature σ.

5. Verification
b ← Vf(pk,t,M,σ) Anyone can verify the message M within the time period t under the public key pk by running the verification algorithm The signature of signature M. This algorithm returns 1 indicating that the signature is valid, otherwise it returns 0.

1. Relying on asymmetric bilinear groups to improve efficiency, our signature is located in G2×G1 instead of G2^2. This way, it is enough to give public parameters into G1 (which we can then use hash curve instantiation without trust setup) without having to generate "consistent" public parameters (hi, h0 i) = (gxi 1, gxi 2) ∈G1×G2.

2. Key generation algorithm, public key pk is smaller, and parameter settings improve security.

In addition to the algorithm for the forward secure signature scheme in Section 3, the forward secure multi-signature scheme FMS in the key verification model also has a key generation that additionally outputsProof of public key π.
Added Key aggregation, Signature aggregation, and Aggregate verification. It also proves its correctness and security on the premise of meeting the multi-signature function of forward security.

1. PoS is protected from subsequent damage
Subsequent damage: Post-verified nodes attack and destroy the previous consensus verification state.
In situations where many users propagate many signatures (such as transaction blocks) on the same message, Pixel can be applied to all of these blockchains to protect against follow-on attacks and potentially reduce bandwidth, storage and computation cost.

2. Pixel integration
In order to vote on block B, each member of the sub-protocol signs B using a Pixel with the current block number. Consensus is reached when we see the set of N committee members signing on the same block B, where N is some fixed threshold. Finally, we aggregate these N signatures into a single multi-signature Σ, and the pair (B, Σ) forms a so-called block certificate and append block B to the blockchain.

3. Register a public key
Every user who wants to participate in the consensus needs to register a participating signing key. Users first sample Pixel key pairs and generate corresponding PoPs. The user then issues a special transaction (signed under her consumption key), registering a new participation key. Transactions include PoP. Select the PoS validator that reached agreement in round r to check (a) the validity of the special transaction and (b) the validity of the PoP. If both checks pass, the user's account is updated with the new participation key. From this point, if checked, the user will use the Pixel login block.
That is, constantly changing its own participation key to achieve forward security.

4. Propagation and aggregation of signatures
The signatures of each committee will be propagated through the network until the signatures of N committee members are seen on the same block B. Note that Pixel supports non-interactive and incremental aggregation: the former means that signatures can be aggregated by any party after broadcast without contacting the original signer, while the latter means that we can add new signatures to a multisig to obtain new of multi-signatures. In practice, this means that the propagating node can perform intermediate aggregation on any number of committee signatures and propagate the results until a block certificate is formed. Alternatively, nodes can aggregate all signatures before writing the block to disk. That is, after receiving enough block certification votes, a node can aggregate the signatures of N committee members into a multi-signature and then write the block and certificate to disk.

5. Key update
When using Pixel in the blockchain, timeCorresponds to a block number or sub-step in the consensus protocol. When relating time to the block number, it means that all eligible committee members should update their pixel keys every time a new block is formed and the round number is updated.

Conduct an experimental evaluation on the Algorand project, and compare it with the Algorand project's own solution to prevent post-corruption attacks, BM-Ed25519, and the BLS multi-signature solution.

Storage space:

Bandwidth saving:
Algorand uses a relay-based propagation model, where the user’s nodes are connected to the relay network (nodes with more resources ). Without aggregation during propagation, the bandwidth pixel savings for relays and regular nodes come from smaller signature sizes. Each relay can serve dozens or hundreds of nodes, depending on the resources it provides.

Save verification time

『撒』 What is blockchain

[Definition]

Blockchain is It refers to a technical solution for collectively maintaining a reliable database through decentralization and trustlessness. This technical solution allows any number of nodes participating in the system to calculate and record all information exchange data in the system over a period of time into a data block (block) through cryptographic algorithms, and generate the fingerprint of the data block for linking ( chain) and check the next data block, all participating nodes in the system jointly determine whether the record is true.

Blockchain is a general term for technical solutions similar to NoSQL (non-relational database). It is not a specific technology. Blockchain technology can be implemented through many programming languages ​​and architectures. . There are also many ways to implement blockchain. Common ones currently include POW (Proof of Work), POS (Proof of Stake), DPOS (Delegate Proof of Stake), etc.

The concept of blockchain was first proposed in the paper "Bitcoin: A Peer-to-Peer Electronic Cash System" by the author who calls himself Satoshi Nakamoto (Satoshi Nakamoto) individual (or group). Therefore, Bitcoin can be viewed as a blockThe first application of blockchain in the field of financial payment.

[Popular explanation]

No matter how big the system or how small the website, there is usually a database behind it. So who will maintain this database? Under normal circumstances, whoever is responsible for operating the network or system will maintain it. If it is a WeChat database, it must be maintained by Tencent's team, and Taobao's database must be maintained by Alibaba's team. Everyone must think that this approach is natural, but this is not the case with blockchain technology.

If we imagine the database as a ledger: Alipay, for example, is a typical ledger, and any change in data is an accounting type. We can think of database maintenance as a very simple accounting method. The same is true in the world of blockchain. Everyone in the blockchain system has the opportunity to participate in accounting. The system will select within a period of time, maybe within ten seconds, or maybe ten minutes, to select the person with the fastest and best accounting during this period. This person will do the accounting, and he will combine the changes in the database during this period with Changes in the ledger are recorded in a block. We can imagine this block as a page of paper. After confirming that the record is correct, the system will link (chain) the data fingerprint of the past ledger to this paper, and then This piece of paper is sent to everyone else in the entire system. Then the cycle starts over and the system looks for the next person who can do the accounting quickly and well, and everyone else in the system gets a copy of the entire ledger. This also means that everyone in this system has exactly the same ledger. This technology is called blockchain technology, also known as distributed ledger technology.

Since everyone (computer) has exactly the same ledger, and everyone (computer) has exactly the same rights, there will be no problem due to a single person (computer) losing contact or going down. The entire system collapses. Since there are exactly the same ledgers, it means that all data is open and transparent, and everyone can see the digital changes in each account. Its very interesting feature is that the data in it cannot be tampered with. Because the system will automatically compare, it will consider the account books with the largest number of the same number as the real account books, and the small number of account books with different numbers as others are false account books. In this case, it makes no sense for anyone to tamper with their own ledger, because unless you can tamper with most of the nodes in the entire system. If the entire system has only five or ten nodes, it may be easy to do, but if there are tens of thousands or even hundreds of thousands of nodes, and they are distributed in any corner of the Internet, unless someone can control most of the computers in the world , otherwise it would be unlikely to tamper with such a large blockchain.

[Elements]

Combined with the definition of blockchain, we believe that it must have the following four elements to be called a public blockchainWhen looking at blockchain technology, if it only has the first three elements, we will consider it to be private blockchain technology (private chain).

1. Point-to-point peer-to-peer network (peer-to-peer power, physical point-to-point connection)

2. Verifiable data structure (verifiable PKC system, non-tamperable database)

3. Distributed consensus mechanism (solve the Byzantine generals problem and double payment)

4. Nash equilibrium game design (cooperation is an evolutionarily stable strategy)
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[Characteristics]

Combined with the definition of blockchain, blockchain will realize four main characteristics: decentralized, trustless, Collectively maintained (Collectively maintained), reliable database (Reliable Database). And the four characteristics will lead to two other characteristics: open source (Open Source) and privacy protection (Anonymity). If a system does not possess these characteristics, it will not be considered an application based on blockchain technology.

Decentralized: The entire network has no centralized hardware or management organization. The rights and obligations between any nodes are equal, and the damage or loss of any node will not affect it. operation of the entire system. Therefore, the blockchain system can also be considered to have excellent robustness.

Trustless: Each node participating in the entire system does not need to trust each other for data exchange. The operating rules of the entire system are open and transparent, and all data contents are also public. , therefore within the rule range and time range specified by the system, nodes cannot and cannot deceive other nodes.

Collectively maintain: The data blocks in the system are jointly maintained by all nodes with maintenance functions in the entire system, and these nodes with maintenance functions can be participated by anyone.

Reliable Database: The entire system will be divided into databases so that each participating node can obtain a copy of the complete database. Unless more than 51% of the nodes in the entire system can be controlled at the same time, modifications to the database on a single node are invalid and cannot affect the data content on other nodes. Therefore, the more nodes and stronger computing power participating in the system, the higher the data security in the system.

Open Source (Open Ssource): Since the operating rules of the entire system must be open and transparent, for the program, the entire system must be open source.

Privacy protection (Anonymity): Since nodes do not need to trust each other, there is no need to disclose their identities between nodes. The privacy of each participating node in the system is protected. protected.

『8』 What is a milestone in the development of blockchain

1. Satoshi Nakamoto’s paper-Bitcoin White Paper

In 2008, it was too loose in the United States Under the credit standards, the huge bubble created by housing loans triggered a series of financial crises that started in September 2008.

On Sunday, September 14, Lehman Brothers declared bankruptcy after the U.S. Federal Reserve refused to provide A-funded support assistance, and on the same day Merrill Lynch announced that it was acquired by Bank of America. These two events marked the starting point of the financial crisis, which in turn triggered the global stock market crash and the Great Financial Recession. Many investors suffered heavy losses and made people begin to distrust the totalitarian financial system.

2. Genesis Block

2009 On January 3, 2018, the first Bitcoin block was born after the first batch of miners obtained 50 Bitcoins through mining. This also marked the official birth of the Bitcoin financial system. But interestingly, in Bitcoin Several years after the advent of blockchain, people discovered a hexadecimal string in line #1616 of Coinbase’s genesis block transaction code.

After converting this string into alphanumeric characters, you will get "sknab rof tuoliab dnoces fo knirb no rollecnahC 9002/naJ/30 semiT ehT". The reverse reading is "The Times 03/Jan/2009" Chancellor on brink of second lout for banks” is the founding date of Bitcoin and the message left by Satoshi Nakamoto in the original transaction.

3. The first Bitcoin payment – ​​PizzaDay

Laszlo Hanyecz is a Floridian and engineer working at the online retail company GoRuck, but if you are in the currency circle, you You must have heard some of his amazing deeds: Hanyecz used 10,000 Bitcoins (BTC) to buy two slices of pizza from Papa John's from netizens on May 22, 2010, which is a $25 pizza. Today, 10,000 Bitcoins are worth approximately for US$40 million.

The person named Jeremy Sturdivant (online name "Jercos") was the one who originally received 10,000 Bitcoins in exchange for two slices of pizza for Hanyecz people. The importance of this transaction is that this is the first time in the history of Bitcoin that physical transactions have been carried out, proving that Bitcoin does have the function of price transfer in the real world.

4. Mt. Gox, the largest exchange hacking incident in history

On February 24, 2014, Mt. Gox was the largest Bitcoin exchange at the time. Mark Karpeles, CEO of the exchange, announced his withdrawal from the Bitcoin Foundation in his blog. Subsequent visits to Mt. Gox will only return a blank page.

On February 28, 2014, Mt. Gox filed for bankruptcy protection with the Tokyo District Court. Data from the bankruptcy research institution "Teikoku Databank, Ltd." showed that Mt. Gox was in debt Reaching 6.5 billion yen, the revenue in 2013 was 135 million yen; Imperial Data Research Company stated in a press release that Mt. Gox subsequently discovered that 100,000 of its own Bitcoins and 750,000 user Bitcoins were stolen.

5. The advent of Ethereum

On July 30, 2015, the first Ethereum was officially launched, named Frontier. All the Ethereum promised to early investors was successfully delivered, and developers began to weave their dreams on Ethereum.

Part II—Constantinople of the third version of Ethereum Metropolis will be launched soon (currently postponed to the middle of next year). Although the current price of Ethereum is less than 10% of this year’s high, In the past three years, we have witnessed the innovations that Ethereum has brought to the world: including the Ethereum Virtual Machine, smart contracts, Dapps, permissioned shared ledgers (Permissioned Ledger), etc.

Although Ethereum is facing expansion difficulties and is still waiting for technological updates, in 17 and 18 years, many underlying public chains emerged as application platforms, that is, many competitors of Ethereum, opening up the "multiple "Chain Era". At present, there are many dApp developers who are turning to other public chains due to the limitations of Ethereum's current TPS. Some people believe that the future will be a scenario of "multiple chains in parallel, one for each chain."

『玖』 There are many blockchain applications now. What kind of blockchain applications are good? Where can I learn more about them?

I want to know about blockchain For chain applications, you can refer to many books and opinions, including "Blockchain in Pictures", "Blockchain: Reshaping the Economy and the World", "New Economic Blueprint and Introduction", as well as articles from the Binance community, including comments on the Binance community I also know this platform in detail, and its strength is awesome.

1. What is blockchain

Blockchain, as the name suggests, is composed of blocks and chains. It is a distributed data storage , point-to-point transmission, consensus mechanism, encryption algorithm and other new application models of computer technology. It is a kind of timeIt is a chain data structure that combines data blocks in a sequential manner, and is cryptographically guaranteed to be an untamperable, unforgeable, safe and trustworthy distributed ledger.

In 2008, Satoshi Nakamoto first proposed the concept of blockchain and encrypted digital currency in his paper "Bitcoin: A Peer-to-Peer Electronic Cash System". Starting from Bitcoin, blockchain has become the underlying technology of various digital currencies.

2. The working principle of blockchain:

1. Basic concepts include:
(1) Transaction: one operation will change the ledger status once , such as adding a record;
(2) Block: records transactions and status data that occurred within a specified time, which is a consensus and preservation of the current ledger status;
(3) Chain ( Chain): It is composed of blocks connected in chronological order and is a log record of the entire state change.
Understanding the working concept of blockchain, it is not difficult to understand its working principle. Suppose there is a distributed data record book. This record book only allows additions, deletions and changes. Its structure is composed of individual data records. "Blocks" are connected in series to form a linear chain (this is also the origin of the name "blockchain"). To add new data, it must be placed in a new block. The maintenance node can propose a new block. However, a certain consensus mechanism must be used to reach agreement on the final selected block.

2. Take Bitcoin as an example to see how the blockchain works.

Bitcoin blocks are divided into two parts: block header and block body.

3. Core advantages and characteristics of blockchain

1. Decentralization
Block The processes of verification, accounting, storage, maintenance and transmission of chain data are all based on the distributed system structure. There is no centralized hardware or management organization. The rights and obligations of any node are equal. The data blocks in the system are composed of Nodes with maintenance functions in the entire system are jointly maintained.
2. Open and transparent
The system is open. In addition to the private information of the transaction parties being encrypted, the blockchain data is open to everyone, and anyone can query the blockchain through the public interface. Data and development related applications, so the entire system information is highly transparent.
3. Security
The blockchain adopts consensus-based specifications and protocols (such as a set of open and transparent algorithms) to enable all nodes in the entire system to exchange data freely and securely in a trustless environment. , so that trust in "people" is changed to trust in machines, and any human intervention has no effect.
4. Information cannot be tampered
Once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% of the nodes in the system (almost impossible) can be controlled at the same time, otherwise Modifications to the database on a single node are invalid, so the blockchainThe data stability and reliability are extremely high.
5. Anonymity
Since the exchange between nodes follows a fixed algorithm, the data interaction does not require trust (the program rules in the blockchain will judge whether the activity is valid by itself), so the counterparty does not need to Making the other party trust you by disclosing your identity is very helpful for the accumulation of credit.

4. Classification of Blockchains

Currently, the most mainstream classification of Blockchains is to divide Blockchains into Public Blockchains based on different participants. ), Private Blockchain and Consortium Blockchain.

1. Public chain: Anyone can participate in the use and maintenance, and can obtain effective confirmation of the blockchain. The public chain is the earliest blockchain and the most widely used blockchain at present. , typically such as the Bitcoin blockchain, the information is completely public.

If a permission mechanism is introduced, it will include private chain and alliance chain.
2. Private chain: A company or individual only uses blockchain technology and has exclusive write permission to the blockchain, and the information is not made public. At present, conservative giants (traditional finance) all want to experiment with private blockchains, and the application products of private blockchains are still being explored.
3. Consortium chain: It is a blockchain between the public chain and the virtual chain, jointly controlled by multiple organizations. The use of this chain is managed with authority and can be controlled by managers and also based on The manager's wishes are open to others.
In addition, according to the different usage scenarios and purposes of blockchain, it is divided into currency chains for the purpose of digital currency, property rights chains for the purpose of recording property rights, crowdfunding chains for the purpose of crowdfunding, etc. .

5. Analysis of specific application scenarios of blockchain

1. Information anti-counterfeiting

On May 28, Tencent CEO Ma Huateng spoke at the Guiyang Digital Expo The problem of Moutai anti-counterfeiting has been raised: the anti-counterfeiting method based on cloud-based comprehensive blockchain technology will be much more efficient than traditional anti-counterfeiting methods. In future anti-counterfeiting verification scenarios, users may only need to perform a simple scan with their mobile phone to obtain a large amount of complete information based on different dimensions.

Take Moutai as an example:

Distillery address, production workshop, operating employees, inspectors, factory time, transportation vehicle information and driver information,

The vintage source of raw materials for wine, raw material suppliers, storage warehouse numbers, raw material transportation vehicles and driver information,

All information can be accurately traced, permanently recorded and cannot be tampered with.

The authenticity can be easily verified based on the above information.

2. Food safety issues

As early as November last year, Walmart had cooperated with IBM to ensure food safety by using blockchain technology to track food sources. and increase the circulation of food to reduce costs. For large-scale enterprises such as Wal-Mart,For supermarkets, in the past, when food safety problems occurred, it took several days to investigate the source of the food in question. After using this technology, only one piece of information about the product is needed to accurately trace the source, including the food origin, inspector, supplier, Important information such as logistics and transportation can quickly detect problems within a few minutes. Currently, products tracked using blockchain include packaging products in the United States and pork in China.

3. Information Security

Blockchain technology is promoting a revolution in information security technology. Three major security threats: man-in-the-middle attack, data tampering, and DDoS

(1) Identity protection

PKI is a common public key encryption used in various communication applications such as email, messaging applications, and websites. technology. However, since most PKI implementations rely on a centralized trusted third-party certification authority (CA) to issue, activate and store user certificates, hackers can attack PKI to fake user identities or crack encrypted information.

CertCoin is the first blockchain PKI implementation, coming from MIT, which removes the centralized certification center and uses the blockchain as a distributed ledger of domain names and public keys.

Pomcor Company: Blockchain PKI implementation path: retain the certification center and use the blockchain to store hash values ​​of issued and activated certificates. Users can verify the authenticity of certificates through decentralized and transparent sources, while also improving network access performance through local authentication of keys and signatures based on blockchain copies.

(2) Data integrity protection

GuardTime has developed a keyless signature architecture (KSI) based on blockchain technology to replace key-based data authentication technology. KSI stores hashes of the original data and files on the blockchain, runs hashing algorithms to verify other copies, and compares the results with the data stored on the blockchain. Any tampering with the data will be quickly detected because the original hash table is stored on millions of nodes.

(3) Protection of critical infrastructure

The "Achilles' heel" of the Internet, DDoS has entered the TB era, and DDoS is still the easiest way for hackers to defeat large targets at low cost. As a weapon, DNS services are the primary target for hackers to carry out large-scale damage, but blockchain technology is expected to fundamentally solve it.

The distributed storage of blockchain makes hacker attacks lose focus. Nebulis is developing a distributed DNS system using the Ethereum blockchain and the InterPlanetary Internet File System (IPFS, a distributed alternative to HTTP product) to register and resolve domain names. The biggest weakness of DNS is caching. Caching makes DDoS attacks possible and is also the bane of centralized governments censoring social networks and manipulating DNS registrations. A highly transparent, distributed DNS system can effectively prevent any entity, including the government, from manipulating records.

4. Financial Industry

(1) Digital Currency: Improving the convenience of currency issuance and use

Such as foreign Bitcoin and Ethereum, our country currently has Guo Renbao and so on.

From the use of physical transactions, to physical currency and credit currency, to the rise of the Bitcoin network, more people are aware of the distributed ledger blockchain technology behind it, and gradually outside of digital currency applied in many scenarios.

(2) Cross-border payment and settlement: realize point-to-point transactions and reduce intermediate costs

Transfer and payment. At present, the most mature application of blockchain technology is payment and transfer. Blockchain technology can avoid complicated systems, save the process of inter-bank reconciliation and review, and speed up settlement; using virtual currency does not require the intervention of a clearing house, reducing transaction fee. The clearing procedures of each country are different. It takes 2 or 3 days for a single remittance to arrive, which is inefficient and accounts for a large proportion of funds in transit. No longer going through a third party, point-to-point payment is formed through blockchain technology. Eliminating the need for third-party institutions, you can make payments throughout the day, receive money in real time, quickly withdraw cash, and reduce hidden costs, helping to avoid financial risks. It is timely and convenient.

(3) Bills and supply chain financial business: reduce human intervention, reduce costs and operational risks

Point-to-point value transfer, physical bills or central system for control and verification; intermediary will be eliminated and human intervention reduced. Improved efficiency, smoother financing channels, lower risks, and benefits for all parties.

(4) Securities issuance and trading: realize quasi-real-time asset transfer and accelerate transaction clearing speed

The application of blockchain technology can make the securities trading process simpler, more transparent and faster , Reduce IT systems with repetitive functions and improve the efficiency of market operations. For stocks, blockchain can eliminate paper and pen or spreadsheet records, reduce human errors in transactions, and improve the transparency and traceability of trading platforms. Citi and Nasdaq collaborate to advance blockchain applications.

(5) Customer credit reporting and anti-fraud: reduce legal compliance costs and prevent financial crimes

Customer information and transaction records recorded in the blockchain help banks identify Abnormal transactions and effectively prevent fraud. The technical characteristics of blockchain can change the existing credit reporting system. When banks perform "know your customer" (KYC), the data of customers with bad records will be stored in the blockchain.

Equity crowdfunding: Equity crowdfunding based on blockchain technology can achieve decentralized trust and investors’ returns are guaranteed.

5. Supply chain management

Distributed ledger system, participants track the ownership of assets throughout the process, and can be used to track auto parts when moving between countries and factories.

Toyota is developing blockchain technology solutions for its core parts supply chain operations. Using a large amount of data helps Toyota more efficiently ensure the accuracy of recorded data and can also help manage the supply chain. At the same time, the blockchain supply chain can control warranty, repair goods-related costs and specifications through smart contracts, and transactions throughout the product life cycle are irrevocable.

The shipping industry’s first public solution solution is provided by Maritime Transport International (MTI) Deployment, using blockchain supply chain technology to share Verified Gross Mass (VGM) information of shipping containers. Information about container VGM is important to ensure ships are properly stowed and to prevent accidents at sea and in ports. VGM data is stored on the blockchain supply chain, providing a permanent record for port officials, shipping companies, shippers and cargo owners. This replaces cumbersome logs, spreadsheets, data brokers and private databases.

Logistics Integrity System Wagonbang Wagonbang launched a blockchain-based financial solution for logistics enterprises, aiming to provide enterprises with reliable financial services. It can not only help drivers solve the problem of loan difficulty, but also change the current situation of lack of integrity in the industry and help build a logistics integrity system. Help build the identity chain of logistics companies and create a trusted data ecosystem for logistics companies. Using a transparent, supervisory, and traceable algorithm model, we screen reliable companies that need financial support and provide them with financial services. On the other hand, at the technical level, various law enforcement departments are linked to jointly punish dishonest companies.

6. Government management

(1) Election

Based on the characteristics of blockchain technology and considering the shortcomings of current election technology, we will build an open source , Blockchain applications for elections, voting and lottery, we call it ElectionChain. We hope to optimize election and voting technology to make voting more open and transparent, reduce human manipulation, and allow voters to verify their election results.

Including identity authentication, multi-chain system, flash investment protocol, consensus algorithm EDPOS, privacy protection, voting mechanism design, decentralized ELC rental market, storage solutions, smart contracts, etc.

(2) Government services

Aiming to realize an e-government digital ecosystem based on blockchain technology and provide citizens with government services and an automated mechanism for the business of various government departments, it must be All areas of national government affairs are combined to form a common information space, including government agencies, economic data, financial transactions and social fields. This ecosystem should also include registries and corresponding software for building smart contract-based applications and platforms for government agencies, businesses and public users.