纽约成立区块链技术中心,去年曾吸引2亿美金风投,美国区块链协会

纽约成立区块链技术中心，去年曾吸引2亿美金风投，美国区块链协会拓展，这三个关键词，堪称区块链技术发展的标志。

纽约是一座充满活力的都市，也是全球金融中心，纽约成立区块链技术中心，正是为了推动区块链技术在金融领域的应用，推动区块链技术的发展。该中心将提供一系列的资源和服务，包括技术培训、投融资、市场营销等，为企业提供全面的支持，帮助企业更好地运用区块链技术。

去年，纽约成立的区块链技术中心吸引了2亿美金的风投，这也是近年来纽约投资者对区块链技术的认可。这笔资金将用于推动纽约区块链技术中心的发展，为企业提供更多的技术支持，推动区块链技术的应用。

美国区块链协会（ABC）是一个非营利性的行业协会，旨在推动区块链技术的发展，推动区块链技术的应用。ABC拥有众多企业会员，并与政府部门和行业组织建立了良好的合作关系，共同推动区块链技术的发展。同时，ABC还邀请行业专家参与活动，举办行业论坛，推动行业技术的交流和沟通。

纽约成立区块链技术中心、去年曾吸引2亿美金风投、美国区块链协会拓展，这三个关键词，恰恰说明了区块链技术的发展趋势，也暗示着区块链技术在未来的发展前景。

① How much does the HTC blockchain smartphone "Exos" cost?

According to foreign media reports, HTC is the latest company to join the blockchain entrepreneurial boom. The company announced Plans to produce a new Android smartphone using blockchain technology. The company named the phone "Exos" and equipped it with a universal digital wallet and security hardware to support cryptocurrencies and decentralized applications.

Xinsheng Chen, founder of HTC Vive, HTC’s virtual reality head-mounted display project, will be responsible for all the company’s blockchain projects. At the global blockchain consensus conference Consensus 2018 held in New York today, Chen Xinsheng said: “We envision building a mobile phone on which you have your own electronic key, you have your own identity and data, and your mobile phone is the center. .”

HTC’s Exos phone may be the world’s second blockchain smartphone. The first blockchain smartphone was launched by Israeli technology company SirinLabs and named Finney. It is a mobile phone that allows people to store and use digital currencies without paying transaction fees. The phone is priced at $1,000.

Source of this article: NetEase Technology Report

② Why is the blockchain so popular

Why is the blockchain so popular
In early February this year, The Weibo account "Sina Finance" posted this: A young man from Hangzhou went on a blind date online, but no girl talked to him for more than a month. Later, he added a "blockchain engineer" label to himself, and the girl stopped talking to him in a few days. to more than 200 private messages.
As the most popular industry nowadays, news about recruiting blockchain talents with a million-dollar annual salary makes headlines from time to time. The blockchain industry is becoming a new blue ocean in the job market.
Blockchain talent is in short supply
Blockchain technology is a product of Bitcoin. In 2008, the founder of Bitcoin, who calls himself Satoshi Nakamoto, proposed the concept of "blockchain". By 2015, this underlying technology of Bitcoin has become the new favorite in the global financial and technology industries, and the demand for relevant talents has also increased. Then it increased dramatically.
U.S. Bloomberg quoted data from the professional social networking site "LinkedIn" as saying that job postings related to blockchain, cryptocurrency and Bitcoin increased at least four times in 2017; on CoinDesk, one of the largest employment websites in the United States , 15 of the 18 most popular industry positions are related to cryptocurrency. Data from the website shows that the number of blockchain technology jobs posted in the United States in 2017 increased by 207% compared with the same period in 2016, and by 631% compared with the same period in 2015. On China's mainstream Internet recruitment apps, there are thousands of recruitment information in the blockchain industry.
Corresponding to the rapid expansion of scale, there is a serious shortage of professional talents. Since blockchain has just been “popular” for two or three years, schools and educational institutions have not yet caught up, and relevant courses are rare. In addition, blockchain is an interdisciplinary industry that places equal emphasis on knowledge and experience, which has improved talent training.There is a greater challenge.
There are two main types of companies hungry for blockchain talent: well-established technology companies and ambitious startups. Bloomberg quoted Griffith Hill, chief recruiter of a blockchain talent team, as saying that the technology software industry and the financial services industry are the two fields with the largest number of blockchain jobs posted on LinkedIn.
Almost all Internet companies are recruiting blockchain front-end architects and blockchain development engineers, including eBay, ESPN and Uber in the United States, and Tencent, Xiaomi, Xunlei, Lenovo, JD.com in China... According to the 2017 Fintech 100 Companies 2018 According to a report released in March 2017, half of the top ten blockchain recruiters in the world in 2017 were Chinese companies, with Ant Financial, Zhongan Technology and Qudian taking the top three spots. Internet finance, computer software, and enterprise services have the strongest demand, accounting for more than 50% of the total.
Traditional companies are also vigorously recruiting blockchain talents to improve their own efficiency or better serve customers. Data from CoinDesk shows that large consulting firms such as Deloitte and IBM are the largest employers in the industry. Deloitte has hired more than 800 people in the blockchain field. IBM is also actively looking for relevant talents. In 2017, the company's number of employees in the blockchain field increased from 400 to 1,600, and it has launched more than 400 blockchain projects, and there are still more than 150 blockchain-related job vacancies.
The geographical distribution of blockchain jobs is closely related to economic level. The American "Forbes" magazine website announced the top 15 blockchain employment cities in the United States in February 2018. New York ranked first, with a job gap of 1,316; followed by San Francisco, Boston, Chicago, etc. Outside the United States, there are 423 vacancies in London, 357 in Singapore, 149 in Toronto and 97 in Sydney. In China, according to statistics from Huxiu.com in February 2018, "Beijing, Shenzhen, Hangzhou and Guangzhou" account for more than 80% of blockchain-related positions in China, of which Beijing ranks first with 44.2%.
The threshold for core positions is high
Blockchain talents are not necessarily “coders”. Of the 800 newly recruited blockchain talents by Deloitte, half are developers or architects, and the other half are business analysts, strategy and technology consultants, accountants, etc. Specifically, recruitment in the blockchain industry mainly includes technology, project, operation, and logistics categories.
Of course, technical positions are the most urgently needed. According to statistics from Huxiu.com in February 2018, R&D positions accounted for 49.34%, followed by operations, marketing, and researchers. Technicians need to be able to build applications on top of the core platform and, ideally, independently develop cryptocurrency platforms such as Bitcoin and Ethereum. To this end, they need to master at least one or more languages ​​such as C, C++, C#, Java, Go, etc., have a deep understanding of the underlying technology of the blockchain, understand various mainstream consensus algorithms, and also understand economic principles, monetary theory, etc. . Want to do blockchain development?The threshold is really not low.
In comparison, the threshold for the other three types of talents is lower and they do not need to have too much industry background. They only require a clear understanding of blockchain knowledge based on their own expertise. If you know some financial knowledge and can perform data analysis, it will be the icing on the cake. From an educational point of view, a master's degree is a necessary stepping stone.
For the blockchain industry, compound talents are undoubtedly the most popular. Therefore, talents who master C++ and Go, and are proficient in cryptography and distributed computing are the most popular at the moment. Most companies will form teams of people with different expertise to make up for their respective shortcomings and gradually learn and grow during the project implementation process.
The blockchain industry is developing extremely rapidly, and one needs to have very strong curiosity and the ability to learn quickly to keep up with the pace of blockchain development. Therefore, youth is the biggest bargaining chip. Talents who have been in the industry for 1 to 3 years are the most sought-after at the moment. This is because this period of time allows a person to accumulate enough experience in blockchain development without being worth so much that employers will be discouraged.
Of course, top talent is always scarce. People who can independently develop cryptocurrency platforms such as Bitcoin and Ethereum are being chased around the world. Some people think that there will be no more than 2,000 such "big names", and some even think that there will be no more than 200 people. The difficulty of this kind of work is equivalent to writing code from scratch to create an operating system that can compete with Android or iOS. What most technicians can do is equivalent to developing apps on the operating system.
Some people make a million dollars a year, and some people make a bottom dollar
Can blockchain practitioners really make "a million dollars a year"? This is indeed true according to data from mainstream recruitment websites. For example, Suning.com offers a monthly salary of 50,000 to 100,000 yuan to "senior blockchain developer", and Keda shares also offers a monthly salary of 85,000 to 100,000 yuan to a "blockchain R&D director." However, Alibaba Health's monthly salary for "blockchain technology experts" is 15,000 to 30,000 yuan, and the "blockchain technology evaluation" position at China Academy of Information and Communications Technology is 10,000 to 20,000 yuan.
It can be seen that salaries in the blockchain industry are also polarized, and the differences are huge. The annual salary of core technical personnel generally starts at 150,000 yuan, and senior "big bulls" can indeed earn more than one million yuan per year, and also enjoy equity or option awards; the income of product, media or administrative personnel is not much different from that of other industries. According to Bloomberg, the market The salary level of marketing positions is at the bottom of the entire blockchain industry, with an average annual salary of only US$63,000, compared with RMB60,000 to RMB120,000 in China.
According to statistics from Huxiu.com, positions with a salary of 120,000 yuan/year account for about 18.6% of the total R&D positions, positions with a salary of 180,000 to 240,000 yuan/year account for about 36.2%, and the remaining 47.8% are distributed Within different salary ranges. Salaries vary greatly between regions. The average annual income of blockchain practitioners in places such as Shanghai and Beijing is about 200,000 yuan, while in Guangdong, Zhejiang, Fujian and other places it is about 160,000 yuan.
Be careful when facing the storm
The current explosive growth of the blockchain industry is mainly due to the intensive influx of capital, which is inevitably reminiscent of the Internet bubble from 1998 to 2000: after the capital carnival, most companies finally exited sadly. The main growth in blockchain jobs comes from the mushrooming of start-up companies. These companies are inevitably good and bad, and many of them use asymmetric information and over-package "empty-glove white wolves".
According to the technology and economic media "Titanium Media", there are currently many recruitment "routines" for domestic blockchain companies. Many companies use "financial freedom" to attract job seekers, promising to reward employees with stock options after financing is in place, and even allow employees to join as "partners." But the actual situation may not be like this - no salary will be paid in the first three months of joining, the actual office area is only 15 square meters, the team only has two or three people, and there are no system regulations and constraints. As for the work content, it is to "plan two to three product promotion plans every day." The "product" is actually the company's own "digital currency". The purpose is to attract retail investors and institutions to subscribe as much as possible. When the number of buyers reaches a certain number Then "encircling" capital institutions to invest is quite a scam.
Titanium Media stated that there are currently countless blockchain companies stationed in incubators in various places, and most of them have not yet received financing, and some even lack corresponding capital flow support; employees are often fresh graduates and those with higher qualifications. The shallow ones are the main ones, and they only talk about "ideals" but not about money; some companies "scam the money and then run away." "These blockchain companies may look prosperous, but in fact they may be very poor, just waiting to use white papers to cut leeks." Faced with the full screen on the recruitment app, "The company's CEO and partners personally lead the team, the team is top-notch, and the atmosphere is good. With slogans such as "over 100 million users, sufficient funds, unlimited development space, option incentives, five insurances and one housing fund, no check-in...", job seekers should remain cautious and calm.
The current “high salary” image of blockchain is partly due to the explosive growth of the industry and the shortage of talents. Against the backdrop of a slowdown in the overall economic situation, it is understandable to seize rare development opportunities and pursue higher salaries, but the risks of plunging into emerging fields that are unfamiliar to most people cannot be ignored. As the industry further develops and matures, and relevant talent training mechanisms are gradually improved, more professionals will enter the industry in the future. If you don't pay attention to improving your own strength and blindly follow the trend, then "annual salary of one million" may be just a myth under the bubble.

③ What consensus mechanisms are currently used in blockchain and what are their respective advantages, disadvantages and scope of application

1. What is the technology of blockchain?

If we assume that the database is a ledger, reading and writing the database can be regarded as a bookkeeping behavior. The principle of blockchain technology is to find the person with the fastest and best bookkeeping within a period of time. This person To keep accounts, and then send this page of information in the ledger 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 (didistributed 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 definition of blockchain, we need these four characteristics to consider it: Decentralized , Trustless, Collectively maintain, 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. Collective maintenance (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. 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.

Traditional intermediaries

Although the 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, people were talking a lot about disintermediation, a new way of connecting 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 technical 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 the blockchain, which has also had a considerable impact on 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.

Decentralized Finance

In 2015, probably due to their high sensitivity to the growth of the alternative finance market, nine investment banks targeted blockchain technology finance. The services jointly developed the open standard. 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 must create a new business model.

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 can almost be predicted that it will definitely be cheaper than the existing sharing economy. By then, the giants will be forced to start response.

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 two-party transactions, so the blockchain is no longer needed. Any "trusted intermediary" or guarantor of credit between strangers.

By 2017, regulators will realize that they need to completely rethink the rules and regulations in 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 that it would lead us into a new inclusive and sustainable economy, and that it would lead us into the post-capital paradigm in the future. a democratizing force. butYes, (so far) that's 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 has a number of core technologies and 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 used in equity, supply chain, points, credit, etc. application in the field.

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 long-term operation of the system, resulting in ledger access Risk of performance degradation.

Multiple asset issuance

Bubi blockchain supports the issuance and transaction of multiple assets by different users. Each asset can track and record the issuer, issuance quantity, and transaction. Circulation and other details.

Joint signature control

Allows multiple users to be set up under the same account, and sets corresponding permissions 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.

On-chain exchanges

Compared with traditional centralized exchanges, in a trading platform built with blockchain, all transactions are verified, completed and saved on the chain. 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.

④ What is the "Bitcoin Consensus Conference"

The "Bitcoin Consensus Conference" is organized by Coindesk, a media and research company in the blockchain field. Guests attending will include people in the blockchain field Experts remember representatives of digital currency development projects, and the number of participants is gradually increasing every year, tickets are also rising all the way. When I was playing stocks before, the teacher from Yingfu Financial School said that he was very professional.

It is worth noting that during the annual meeting, the price of Bitcoin will fluctuate significantly, and it has also become a hot spot for the Bitcoin market to follow the rise.

⑤ Why blockchain needs a consensus mechanism

Jinwowo Network Technology analysis believes that in a distributed system, multiple hosts form a network cluster through asynchronous communication. In such an asynchronous system, state replication is required between hosts to ensure that each host reaches a consistent state consensus.

In a distributed system, when multiple hosts pass through an asynchronous system, there may be a faulty host that cannot communicate, the performance of the host may be degraded, and the network may be congested, which may cause error information to spread within the system. Therefore, it is necessary to define a fault-tolerant protocol in an asynchronous network that is unreliable by default to ensure that each host reaches a safe and reliable state consensus.

Using blockchain to construct a decentralized ledger based on the Internet, the primary problem that needs to be solved is how to achieve the consistency and correctness of ledger data on different ledger nodes.

This requires learning from existing algorithms for achieving state consensus in distributed systems, determining the mechanism for selecting accounting nodes in the network, and how to ensure that ledger data forms a correct and consistent structure throughout the network. consensus.

⑥ Four consensus mechanisms of blockchain

The consensus mechanism of blockchain can be divided into the following four categories: Proof of Stake mechanism, Proof of Work mechanism, Pool verification and pool shares Authorization certification mechanism.
Blockchain is a chain composed of blocks one after another. Each block stores a certain amount of information, and they are connected into a chain in the order in which they were generated. This chain is saved in all servers. As long as one server in the entire system can work, the entire blockchain is safe. These servers are called nodes in the blockchain system, and they provide storage space and computing power support for the entire blockchain system.

⑦ How to better understand the consensus mechanism in the blockchain

Jin Wowo explained with a vivid metaphor: If consensus is the basis of the blockchain, then consensus Mechanism is the soul of blockchain.
When explaining what a blockchain is, it can be summarized with a concise and clear decentralized distributed ledger, but in this ledger, how are things generated in almost the same time sorted forward and backward? , involving the consensus mechanism of the blockchain network.
So Jinwowo Network Technology believes that the consensus mechanism is an algorithm that reaches consensus on the order of things within a period of time.

⑧ "Link to the Future: Embrace the New Era of Blockchain and Digital Assets" epub download and read online, please ask for Baidu Netdisk cloud resources

"Link to the Future: Embrace the New Era of Blockchain and Digital Assets" The New Era of Digital Assets" (Xu Zijing) E-book network disk download for free online reading

Resource link:

Link:

Book title: Link to the Future: Embrace the New Era of Blockchain and Digital Assets Times

Author: Xu Zijing

Douban score: 6.4

Publisher: Machinery Industry Press

Publication year: 2018-3< /p>

Number of pages: 200

Content introduction:

Systematically introduce blockchain from the aspects of origin, principle, technical foundation, application, new development, prospect prediction, etc. In particular, it focuses on introducing some new achievements of blockchain, new industry trends, and systematically introduces the current status of digital currency.

This book can be used not only as a study manual for digital currency enthusiasts, but also as an entrepreneurial guide for entrepreneurs from all walks of life, especially in related fields.

About the author:

Xu Zijing, a well-known representative in the blockchain industry, founder of Australian Branch Bank Capital, co-founder of Australian Blockchain International, honorary chairman of the Super Cash Foundation, An early investor in digital currency, he played a decisive role in the development of digital assets in Asia and Australia. In recent years, he has been committed to promoting the ecological construction of multiple heavyweight projects.

Cheng Jianbo, a well-known pioneer in the blockchain and cloud computing industry, has extensive experience in strategic planning and operation of blockchain enterprises, and is a member of the ADCA Committee of the Australian Blockchain Association. Mr. Cheng serves as the chief strategy officer of the Australian blockchain project Hcash and led the writing of Hcash's white paper. He initiated and promoted the top blockchain joint laboratories of Monash University, Hong Kong Polytechnic University and Purdue University, which was the earliest in Australia. Well-known industry leaders who have entered the blockchain field.

Wei Jiusheng holds dual master's degrees in accounting and finance from Monash University, Australia's top business school. He is a partner of Australia's Corinth Capital and the founder of Australia's first compliant digital asset crowdfunding platform. It has Australia’s only blockchain digital currency venture capital license. Participated in the New York Consensus Conference with the Australian government delegation. In recent years, he has been engaged in venture capital investment in the blockchain industry and served as a business consultant for multiple blockchain projects.

Chang Hao focuses on the construction of community ecosystem and brand marketing for blockchain projects. He has provided professional brand strategy consulting and integrated marketing plans for dozens of well-known domestic and foreign companies and brands for more than ten years. Founded H1percent in 2017, focusing on community ecological construction of blockchain industry projects, and received investment from multiple venture capital institutions.

⑨ Three common consensus mechanisms in blockchain

Blockchain is a distributed ledger system built on P2P network and participated by nodes. The largest The characteristic is "decentralization". That is to say, in the blockchain system, there is no need to establish trust between users, between users and institutions, and between institutions. Transactions can be realized by relying only on the blockchain protocol system.

However, how to ensure the accuracy, authority, and reliability of the ledger? Why do nodes on the blockchain network participate in accounting? What should I do if the node is fake? How to prevent the ledger from being tampered with? How to ensure data consistency between nodes? …These are the problems that blockchain needs to solve when establishing “decentralized” transactions, resulting in the consensus mechanism.

The so-called "consensus mechanism" is to complete the verification and confirmation of transactions in a very short time through the voting of special nodes; when there is a disagreement, without central control, several Nodes participate in decision-making to reach consensus, that is, how to establish a trust relationship between individuals who have no basis for trust in each other.

Blockchain technology uses a set of consensus-based mathematical algorithms to establish a "trust" network between machines, thereby creating new credit through technical endorsement rather than centralized credit institutions.

Different blockchain types require different consensus algorithms to ensure that the last block on the blockchain can reflect the status of the entire network at any time.

So far, the blockchain consensus mechanisms mainly include the following: POW workload proof, POS equity proof, DPOS authorized equity proof, Paxos, PBFT (Practical Byzantine Fault Tolerance Algorithm), dBFT, DAG ( Directed acyclic graph)

Next, we will mainly talk about the principles and application scenarios of common POW, POS, and DPOS consensus mechanisms

Concept:

Proof of work was originally an economic term, referring to the measurement method set up by the system to achieve a certain goal. A simple understanding is a certificate to confirm that you have done a certain amount of work, and to prove that the corresponding amount of work has been completed by certifying the results of the work.

The proof-of-work mechanism has the advantage of complete decentralization. In a blockchain with a proof-of-work mechanism as the consensus, nodes can enter and exit freely and calculate the numerical solution of the random hash. The ability to compete for accounting rights and obtain correct numerical solutions to generate blocks is a concrete manifestation of node computing power.

Applications:

The most famous application of POW is Bitcoin. In the Bitcoin network, during the Block generation process, miners need to solve complex cryptographic mathematical problems to find a Block Hash that meets the requirements, consisting of N leading zeros. The number of zeros depends on the difficulty value of the network. During this period, a lot of trial calculations (workload) are required, and the calculation time depends on the hashing speed of the machine.

Finding a reasonable hash is a probabilistic event. When a node has n% of the computing power of the entire network, the node has a probability of n/100 to find the Block.Hash. After the node successfully finds a satisfactory Hash value, it will immediately broadcast the packaged block to the entire network. The nodes in the network will verify it immediately after receiving the broadcast packaged block.

If the verification passes, it means that a node has successfully solved the puzzle, and it will no longer compete for the current block, but choose to accept the block, record it in its own ledger, and then proceed to the next block. Competitive guessing game of blocks. Only the fastest puzzle-solving block in the network will be added to the ledger, and other nodes will copy it, thus ensuring the uniqueness of the entire ledger.

If a node engages in any cheating behavior, it will cause the network node verification to fail and directly discard its packaged block. This block will not be recorded in the general ledger, and the cost of the cheating node will be It is all in vain. Therefore, under the huge mining cost, miners voluntarily comply with the consensus protocol of the Bitcoin system, thus ensuring the security of the entire system.

Advantages and Disadvantages

Advantages: The results can be verified quickly, the system bears a large number of nodes, and the cost of evil is high to ensure the conscious compliance of miners.

Disadvantages: It requires a large amount of algorithm consumption, and it takes a long time to reach consensus

Concept:

Proof of Stake mechanism (Proof of Stake), requirements A certifier provides ownership of a certain amount of cryptocurrency.

The way the proof-of-stake mechanism works is that when a new block is created, the miner needs to create a "coin rights" transaction, which will send some coins to the miners themselves according to a preset ratio. The proof-of-stake mechanism reduces the mining difficulty of nodes in equal proportions based on the proportion and time of tokens owned by each node based on the algorithm, thus speeding up the search for random numbers.

Application:

In 2012, a netizen with the pseudonym Sunny King launched Peercoin, which was the first application of the proof-of-stake mechanism in encrypted electronic currency. The biggest innovation of PPC is that its mining method mixes POW and POS methods, uses a proof-of-work mechanism to issue new coins, and uses a proof-of-stake mechanism to maintain network security.

In order to implement POS, Sunny King learned from Satoshi Nakamoto’s Coinbase and designed a special type of transaction called Coinstake.

The picture above shows how Coinstake works. Coin age refers to the holding period of the currency. If you own 10 coins and hold them for 10 days, then you have collected 100 days of coins. age. If you use these 10 coins, the coin age is consumed (destroyed).

Advantages and Disadvantages:

Advantages: shortens the time required to reach consensus and is more energy-saving than proof of work.

Disadvantages: Essentially, nodes in the network are still required to perform mining operations, and the authenticity of transfers is difficult to guarantee

Concept:

Authorized equity certificate Mechanism (Delegated Proof of Stake) is similar to board voting. This mechanism has a built-in real-time shareholder voting system, just like the system is convening a never-ending shareholders' meeting at any time, where all shareholders vote to decide company decisions.

While trying to solve the problems of traditional PoW and PoS mechanisms, authorized proof of equity can also offset the negative effects of centralization by implementing technological democracy. The decentralization of the blockchain established based on the DPoS mechanism relies on a certain number of representatives rather than all users. In such a blockchain, all nodes vote to elect a certain number of node representatives, who act on behalf of all nodes to confirm blocks and maintain the orderly operation of the system.

At the same time, all nodes in the blockchain have the power to remove and appoint representatives at any time. If necessary, all nodes can vote to disqualify the current node representatives and re-elect new representatives to achieve real-time democracy.

Application:

Bitshare is a type of cryptocurrency that uses the DPOS mechanism. By introducing the concept of witnesses, witnesses can generate blocks, and everyone who holds BitShares can vote for witnesses. Candidates who get the top N (N is usually defined as 101) candidates in the total number of consent votes can be elected as witnesses. The number of elected witnesses (N) must meet: at least half of the participating voters believe that N has been fully decentralized. .

The candidate list of witnesses is updated every maintenance cycle (1 day). The witnesses are then randomly arranged, and each witness has 2 seconds of permission time to generate a block in order. If the witness cannot generate a block in a given time slice, the block generation permission is given to the witness corresponding to the next time slice. . This design of DPoS makes the generation of blocks faster and more energy-saving.

DPOS makes full use of the votes of shareholders to reach consensus in a fair and democratic way. The N witnesses they voted for can be regarded as N mining pools, and these N mining pools Each other's rights are completely equal. Shareholders can change these witnesses (mining pools) at any time by voting, as long as the computing power they provide is unstable, the computer is down, or they try to use their power to do evil.

Advantages and Disadvantages:

Advantages: Reduce the number of nodes participating in verification and accounting, thereby achieving second-level consensus verification

Disadvantages: The degree of centrality is weak, and the security is weaker than POW. At the same time, the node agents are artificially selected, and the fairness is lower than POS. At the same time, the entire consensus mechanism still relies on the additional issuance of tokens to maintain agent nodes. stability.