区块链子,ⅰbc区块链

ⅰbc区块链是一种分布式账本技术，它可以支持多个账户共享可验证的数据。它提供了一种可信赖的、安全的和可验证的机制，用于价值传输和记录交易。本文将介绍ⅰbc区块链拓展的三个关键词：智能合约、挖矿和去中心化。

智能合约是指在区块链上运行的一种自动执行的计算机程序，它可以在双方之间自动执行一项或多项协议。智能合约可以被用来执行各种合同，例如购买协议、贷款协议等。它们可以用来保护双方的利益，并确保双方遵守协议。智能合约可以被用来执行任何规则，并且可以被设计成自动执行，从而可以更有效地执行协议。

挖矿是指在区块链上进行数字货币挖矿的过程。挖矿是一种计算机过程，它可以在区块链上产生新的数字货币，以及产生新的交易。挖矿是一种竞争性的过程，参与者需要使用计算机资源来解决复杂的数学问题，以便产生新的数字货币和交易。挖矿者可以从中获得奖励，这可以作为激励参与者参与挖矿过程。

去中心化是指没有中央组织或机构控制的一种网络结构。去中心化的网络可以让用户之间直接进行交易，而不需要经过中央机构或组织的审查和审批。ⅰbc区块链是一种去中心化的网络，它使用分布式账本技术，可以让用户之间进行安全、可验证的数据共享。去中心化的网络不仅可以提高数据安全性，而且可以提高数据共享的效率和可靠性。

ⅰbc区块链是一种分布式账本技术，它可以支持多个账户共享可验证的数据。它的三个关键词是智能合约、挖矿和去中心化，它们可以改善数据安全性、数据共享效率和可靠性，更好地支持价值传输和记录交易。

A. What are the characteristics and operating mechanisms of blockchain?

Blockchain is a shared distributed database technology. Although the one-sentence introduction to blockchain is worded differently in different reports, the following four technical features are consistent. x0dx0a1. Decentralized: The left side of Figure 1 describes the centralized characteristics of today’s financial system, and the right side describes the emerging decentralized financial system, which has no intermediaries and the rights and obligations of all nodes. Equally, if any node stops working, it will not affect the overall operation of the system; Within the rules and time range, nodes cannot deceive each other; x0dx0a3. Collectively Maintain: The system is jointly maintained by all nodes with maintenance functions, and everyone in the system participates in the maintenance work; x0dx0a4. Reliable database (Reliable Database): Each node in the system has the latest complete database copy. Modifying the database of a single node is invalid because the system will automatically compare and consider the same data record that appears the most times to be true. x0dx0aThe blockchains of projects such as Bitcoin, Ethereum, and DECENT all have these characteristics.

B. Getting Started with Blockchain What You Need to Know!

What is a blockchain?
Literally: a blockchain is a chain composed of small blocks that record various information, similar to what we will Bricks are stacked one after another, and they cannot be removed after being stacked. Each brick also has various information written on it, including: who stacked it, when it was stacked, what material the brick was made of, etc. You can use this information There is no way to modify it.
From a computer perspective: Blockchain is a relatively special distributed database. A distributed database stores data information on each computer separately, and the stored information is consistent. If one or two computers in Taiwan are broken, the information will not be lost, and you can still view it on other computers.
Blockchain is distributed, so it has no central point. Information is stored in all nodes that join the blockchain network, and the data of the nodes is synchronized. A node can be a server, laptop, mobile phone, etc.
What you need to know is that the data stored in these nodes are exactly the same.
Blockchain Features
Decentralization: Because it is distributed storage, there is no central point. It can also be said that each node is a central point. Applications in life do not require a third-party system (bank , Alipay, real estate agencies, etc. are all third parties).
Openness: The system data of the blockchain is open and transparent, and everyone can participate, such as rentingFor a house, you can know the previous rental information of this house and whether there have been any problems. Of course, some personal private information here is encrypted.
Autonomy: The blockchain adopts consensus-based specifications and protocols (such as a set of open and transparent algorithms), and then each node operates according to this specification, so that everything is done by machines, and there is no human touch. Element. This changes trust in people to trust in machines, and any human intervention has no effect.
Information cannot be tampered with: If the information is stored in the blockchain, it will be saved permanently and there is no way to change it. As for the 51% attack, it is basically impossible to achieve.
Anonymity: There is no personal information on the blockchain, because it is all encrypted and is a string of letters and numbers, so your ID card information and phone number will not be resold. Phenomenon.
Block structure
A block contains two parts:
1. Block header (Head): records the meta-information of the current block
2. Block body (Body): actual data
>Contains data as shown below:
How blockchain works
Let’s take transfer as an example:
Currently our transfers are centralized, and the bank is a centralized ledger. For example, there is 400 in account A There are 100 yuan in account B.
When A wants to transfer 100 yuan to B, A needs to submit a transfer application through the bank. After the bank verification is passed, 100 yuan will be deducted from A's account and 100 yuan will be added to B's account.
After calculation, the balance of account A after deducting 100 is 300 yuan, and the balance of account B after adding 100 is 200 yuan.
The steps for transferring money on the blockchain are: A wants to transfer 100 yuan to B. A will tell everyone about the transfer on the Internet, and everyone will check whether there is enough money in A's account. To complete the transfer, if the verification is passed, everyone will record this information in the blockchain on their computers, and the information recorded by everyone will be synchronized and consistent, so that A will successfully transfer 100 yuan to on B’s account. You can see that there is no bank involved.
Related questions
What is the relationship between blockchain and Bitcoin?
Bitcoin was proposed by Satoshi Nakamoto in 2009, and then the blockchain technology was refined with reference to the implementation of Bitcoin.
If Bitcoin is noodles, then blockchain is flour. Later, everyone discovered that flour can be used to make steamed buns and steamed buns in addition to noodles.
Why do I need to help you store block information?
I don’t have time to do it without profit. To put it simply, you help me store information and I will give you corresponding rewards.
Key technical points that need to be understood in blockchain?
Use Hash and asymmetric encryption to ensure that data cannot be tampered with:
Hash: y = hash(x), perform a hash operation on x to obtain y , the original information x can be hidden, because you can't calculate x from y, thus achieving anonymity.
Asymmetric encryption: The public key and the private key are a pair. If the public key is used to encrypt the data, only the corresponding private key can be used to decrypt it; if the private key is used to encrypt the data, then only It can be decrypted with the corresponding public key.
Consensus algorithm: Ensure data consistency between nodes.
Is there a sentence or two that can explain the blockchain?
Yes.
Mahjong is a traditional Chinese blockchain project. A group of four miners work together. The miner who first collides with the correct hash value of 13 numbers can obtain the accounting rights and be rewarded.

C. What exactly is blockchain? Which blockchains have physical applications

What is blockchain?

Official definition: Blockchain is a new application model of computer technology such as distributed data storage, point-to-point transmission consensus mechanism encryption algorithm, etc. The so-called consensus mechanism is a mathematical algorithm that establishes trust and obtains rights and interests between different nodes in the blockchain system.

Vernacular understanding: A block is to package all the data generated within a time period in chronological order. Generally, the length of a block is 10 minutes, which means that within 10 minutes, all the data on the Internet will The data is packed into a complete package, and this complete data package is called a block. The blockchain links these data packages in order to form a structure, and cryptographically ensures that it cannot be tampered with or forged to form a distribution. ledger, this is the blockchain.

It seems that everyone has a preliminary knowledge and understanding of the blockchain. So whether the blockchain has any practical application in daily life, the answer is yes, the current practical application There are mainly the following aspects. Of course, I may not know some of them. Friends are welcome to leave messages to add.

Financial Industry

Blockchain should be used the most in the financial industry.

For example, in May 2017, OMG (Omise Coin) announced that it would cooperate with Alipay to launch an electronic wallet, integrating the "Alipay" payment solution into its own payment service suite to help local electronics in Thailand. Business merchants accept online payment transactions from Chinese tourists.

Another example is PPT, which is a financial transaction system for bills based on blockchain.

Gaming

The gambling industry entered the blockchain probably last year. Why does gambling favor blockchain? Because blockchain provides a relatively fair betting system. Why? It is relatively fair. As can be seen from the previous introduction, the blockchain cannot be tampered with or forged.

For example, WICC (WikiChain) can realize rich application scenarios such as asset issuance, betting applications, copyright traceability, mutual insurance, decentralized exchanges, and cross-border settlement.

For example, the STX (King of Fighters Coin) stox application is designed to provide the full functionality of a prediction market application without any need forcentral server. Prediction markets require functions such as event planning, market production, providing information and analysis to traders, reporting event results, and of course collection and payment.

I believe that if the current lottery industry is built on the blockchain, people will become more and more enthusiastic about buying, because there are too many insider tips that make people give up.

Internet of Things

The Internet of Things still has many applications on the blockchain, because the traceability and immediacy of blocks are very suitable for this industry.

For example, DATA is the concept of the Internet of Things. It is a decentralized p2p network. Data sources can connect to any node in the entire network, then publish data, and the network will immediately send it to subscribers. Horizontal scalability is achieved through sharding pattern. This timeliness and accuracy are very important in IoT applications.

Game industry

For example, GTC (G coin) is a decentralized digital asset based on Ethereum erc20 issued by Game Global. G coin is committed to becoming a universal number in the global game industry. Monetary standards.

For example, MANA is a distributed shared virtual platform. On this platform, users can browse and discover content and interact with other people and entities. Users can also claim ownership of virtual territories through a blockchain-based land ledger. The territory is demarcated by rectangular coordinates (x, y), and its owner can decide the content published on the territory, including static 3D scenes to interactive systems such as games.

There are many other industries. The emperor did not list them one by one, but listed a few representative ones. What is the purpose? It shows that the blockchain is definitely not just a currency transaction, it is a real implementation project, and it is a product of the changes of the times with real practical uses.

The development of human society is actually like the blockchain, it is irreversible and unstoppable. As far as I feel, the blockchain will enter thousands of households sooner or later. Regardless of whether it is bull or bear, hold it in your hands. Value coins and Flush have started quoting digital currencies, which shows that society is accepting it step by step. The power of social development cannot be blocked by any country or person.

D. Interpretation Lesson 3: Blockchain

There was a Bitcoin craze a few years ago, and readers may have heard of blockchain at that time. , however, recently, domestic and foreign financial institutions have begun to study and launch financial services based on blockchain technology. What is so special about it that can attract the favor of formal financial institutions?

Decentralized accounting system

Blockchain is one of the core technologies of Bitcoin. Its most important feature is its ability to create an unchangeable and unchangeable account. A centralized, highly transparent, and anonymous accounting system can provide low-cost, high-security transfer services, and can further be used as a financial management tool.

To understand the blockchain, we must first start with how it works. Bitcoin applicationsFor example, during each transaction, the system will seal the transaction content and related information into a set of blocks, and arrange all the blocks according to time to produce a so-called blockchain.

Since the blockchain records the information of every transaction in the world in detail, you can figure out which "wallet" is just by counting from the first data to the last data. How much "money" do you have.

It should be noted that the blockchain does not directly store the balance in each "wallet", but the flow of "money" in each transaction. Therefore, when querying the balance, you only need to verify the area By counting the authenticity of each piece of information in the blockchain, the final balance of each "wallet" can be obtained.

Since generating blocks requires complex cryptographic calculations, if a centralized server is used for calculations, many high-performance computers will need to be prepared to meet the demand. However, Bitcoin’s approach is to distribute operations to all computers that perform “mining.” These computers are called nodes and will receive a certain amount of rewards after verifying transactions and encapsulating blocks. Therefore, there will be many miners trying to earn Bitcoins. Bitcoins are put into computers for calculation, so that no specific server is needed, but all calculation work is distributed to various nodes of the Bitcoin network.

▲The blockchain is formed by connecting many blocks in series. Since it can record transfers from the first to the last and has a high degree of security, it is very suitable for financial applications. . (Image source: Bitcoin: A Peer-to-Peer Electronic Cash System)

It is theoretically possible to crack, but in practice it is not feasible

In the block During the operation of the chain, all nodes will jointly verify each newly added block to ensure the correctness of the transaction. When the block information recorded by some nodes does not match that of other nodes, other nodes will not recognize the transaction. , so transaction records will not be written to the blockchain.

However, the security of blockchain is not theoretically unbreakable. As long as someone can control more than half of the computing performance of the entire network (that is, control 51% of the computing performance), it can create fake transaction records and ensure that it can complete the block operation before other nodes complete the operation and raise objections. The data is written to the blockchain so that it can modify its own transaction records and reuse the same bitcoin for payment.

Using video games as a simple example, this attack is like using a cheat, which can modify the money to never decrease.

However, from a practical point of view, there are many users of Bitcoin, so there are quite a few nodes in the network, including many professional miners who use special computers to perform calculations, so the computing power of all nodes The total value is quite large, and it is difficult for ordinary people or organizations to grasp 51% of computing performance by themselves.

Assume that all nodes are currently runningThe total computing power is equivalent to 100 supercomputers, so the attacker needs to prepare 101 supercomputers to obtain more than half of the computing performance, which is unlikely to be achieved in the implementation situation.

Taking a step back, assuming that someone can really control more than half of the computing performance, then he can also monopolize the issuance of Bitcoin and transaction fees, and earn considerable profits from it. On the contrary, if If he chose to tamper with the transaction data, Bitcoin users would lose confidence in this currency, causing the value of Bitcoin to collapse, or even "banknotes turning into wallpaper" overnight.

Therefore, assuming that the attacker is motivated by profit, then even if he can launch a 51% attack, he will not do so. This will ensure that Bitcoin and the blockchain are still safe.

▲Bitcoin is one of the most representative application examples of blockchain.

Example of using Shuowenjiezi: Blockchain

O: Blockchain can distribute the load of verifying transactions to everyone in the network node.

X: After parking the bicycle, remember to lock it with the blockchain.

E. What are the core blockchain technologies of blockchain technology?

What is the hottest topic on the Internet right now? You don’t need to explain it to the editor to know that it is the blockchain technology. Blockchain technology, but many friends have only heard of this technology and do not have much in-depth understanding of it. So what are the blockchain technologies? Below we will bring you an introduction to the core technology of blockchain for your reference.
What are the core elements of blockchain technology?
Blockchain technology can be a public ledger (visible by anyone) or a permissioned network (visible only by those authorized), which solves supply chain challenges , because it is an immutable record that is shared among network participants and updated in real time.
Blockchain technology----data layer: designing the data structure of the ledger
Core technology 1. Block + chain:
Technically speaking, block is a data structure that records transactions. Reflects the flow of funds for a transaction. The blocks of transactions that have been reached in the system are connected together to form a main chain, and all nodes participating in the calculation record the main chain or part of the main chain.
Each block consists of a block header and a block body. The block body is only responsible for recording all transaction information in the previous period, mainly including the number of transactions and transaction details; the block header encapsulates the current version number, previous A block address, timestamp (recording the time when the block was generated, accurate to seconds), random number (recording the value of decrypting the answer to the math question related to the block), target hash value of the current block, and Merkle number Root value and other information. From a structural point of view, most functions of the blockchain are implemented by the block header.
Core technology 2. Hash function:
The hash function can calculate data of any length through HashThe method is converted into a set of fixed-length codes. The principle is based on a cryptographic one-way hash function. This function is easy to verify, but difficult to crack. Usually, the industry uses y=hash(x) to represent it. This hash function implements operations on x to calculate a hash value y.
Commonly used hash algorithms include MD5, SHA-1, SHA-256, SHA-384 and SHA-512, etc. Taking the SHA256 algorithm as an example, inputting any string of data into SHA256 will result in a 256-bit Hash value (hash value). Its characteristics: the same data input will get the same result. As long as the input data changes slightly (for example, a 1 becomes a 0), a completely different result will be obtained, and the result cannot be predicted in advance. Forward calculation (calculating the corresponding Hash value from the data) is very easy. Reverse calculation (cracking) is extremely difficult and is considered impossible under current technological conditions.
Core technology 3. Merkle tree:
Merkle tree is a hash binary tree, which can be used to quickly verify the integrity of large-scale data. In the blockchain network, the Merkle tree is used to summarize all transaction information in a block, and ultimately generates a unified hash value of all transaction information in the block. Any change in transaction information in the block will cause Merkle tree changes.
Core technology 4. Asymmetric encryption algorithm:
Asymmetric encryption algorithm is a key secret method that requires two keys: public key and private key. The public key and the private key are a pair. If the public key is used to encrypt data, only the corresponding private key can be used to decrypt it, thereby obtaining the corresponding data value; if the private key is used to sign the data, then only the corresponding public key can be used to sign the data. In order to verify the signature, the sender of the verification information is the holder of the private key.
Because encryption and decryption use two different keys, this algorithm is called an asymmetric encryption algorithm, while symmetric encryption uses the same key in the encryption and decryption processes.
Blockchain technology----network layer: realize the decentralization of accounting nodes
Core technology 5. P2P network:
P2P network (peer-to-peer network), also known as point-to-point technology, is no Central server, Internet system that relies on user groups to exchange information. Unlike a centralized network system with a central server, each client in a peer-to-peer network acts as both a node and a server. Domestic Xunlei software uses P2P technology. The P2P network has the characteristics of decentralization and robustness.
Blockchain technology----Consensus layer: allocate the task load of accounting nodes
Core technology 6. Consensus mechanism:
Consensus mechanism is how to reach consensus among all accounting nodes to identify The validity of a record is both a means of identification and a means of preventing tampering. There are currently four main types of consensus mechanisms: PoW, PoS, DPoS and distributed consensus algorithms.
PoW (ProofofWork, workloadProof): PoW mechanism, which is like Bitcoin’s mining mechanism, miners package existing transactions that have not been recorded by the network into a block, and then continue to traverse and try to find a random number, so that the new block plus the random number The hash value meets certain difficulty conditions. Finding a random number that meets the conditions is equivalent to determining the latest block of the blockchain, and is also equivalent to obtaining the current round of accounting rights of the blockchain. Miners broadcast blocks that meet the mining difficulty conditions in the Yuanfu network. After verifying that the block meets the mining difficulty conditions and that the transaction data in the block meets the protocol specifications, other nodes in the entire network will each Blocks are linked to their own version of the blockchain, thereby forming a network-wide consensus on the current network state.
PoS (Proof of Stake, Proof of Stake): PoS mechanism, a distributed consensus mechanism that requires nodes to provide proof of a certain number of tokens to obtain competition for blockchain accounting rights. If you rely solely on the token balance to determine the bookkeeper, you will inevitably make the rich win, which will lead to the centralization of bookkeeping rights and reduce the fairness of the consensus. Therefore, different PoS mechanisms use different methods to increase the amount of money based on the proof of equity. The randomness of accounting rights avoids centralization. For example, in the PeerCoin PoS mechanism, the Bitcoin with the longest chain age has a greater chance of obtaining accounting rights. NXT and Blackcoin use a formula to predict the next accounting node. The more tokens you own, the greater the probability of being selected as an accounting node. In the future, Ethereum will also switch from the current PoW mechanism to a PoS mechanism. Judging from the information currently available, Ethereum's PoS mechanism will use nodes to place bets on the next block. The winner of the bet will receive an additional Ethereum currency award. Those who do not win will be deducted Ether coins to reach consensus on the next block.
DPoS (DelegatedProof-Of-Stake, share authorization certificate): DPoS is easy to understand and is similar to the modern corporate board of directors system. The DPoS mechanism adopted by BitShares is that shareholders vote to select a certain number of witnesses. Each witness has two seconds of authority to generate blocks in order. If the witness cannot generate a block within the given time slice, The block generation authority is given to the witness corresponding to the next time slice. Shareholders can replace these witnesses at any time by voting. This design of DPoS makes the generation of blocks faster and more energy-saving.
Distributed Consistency Algorithm: Distributed Consistency Algorithm is based on traditional distributed consistency technology. Among them are Byzantine fault-tolerant algorithms that solve the Byzantine Generals problem, such as PBFT (Byzantine fault-tolerant algorithm). In addition, distributed consensus algorithms (Pasox, Raft) that solve non-Byzantine problems are not explained in this article. This type of algorithm is currently a commonly used consensus mechanism in alliance chain and private chain scenarios.
Taken together, POW is suitable for public chains. If you build a private chain, it is more appropriate to use POS because there is no trust problem in verification nodes; while the alliance chain has untrustworthy local nodes.It is more appropriate to use DPOS.
Blockchain technology----Incentive layer: Develop a "salary system" for accounting nodes
Core technology 7. Issuance mechanism and incentive mechanism:
Take Bitcoin as an example. Bitcoins are initially rewarded by the system to miners who create new blocks, and this reward is halved approximately every four years. At the beginning, miners were rewarded with 50 Bitcoins for each new block recorded, and this reward is halved approximately every four years. By analogy, by around AD 2140, newly created blocks will no longer receive rewards from the system. By then, the total number of Bitcoins will be approximately 21 million. This is the total number of Bitcoins, so it will not increase indefinitely.
Another source of incentives is transaction fees. When there are no system rewards for newly created blocks, the miners' income will change from system rewards to transaction fees. For example, when you transfer, you can specify 1% of it as a handling fee to be paid to the miner who records the block. If the output value of a transaction is less than the input value, the difference is the transaction fee, which will be added to the incentive for that block. As long as a given amount of electronic currency has entered circulation, the incentive mechanism can gradually be converted to rely entirely on transaction fees, so there is no need to issue new currency.
Blockchain technology----contract layer: giving the ledger programmable features
Core technology 8. Smart contract:
Smart contract is a set of programmed rules and logic that respond to scenarios. Implemented by decentralized, trusted shared script code deployed on the blockchain. Usually, after the smart contract is signed by all parties, it is attached to the blockchain data in the form of program code, and is recorded in a specific block of the blockchain after being propagated through the P2P network and verified by nodes. Smart contracts encapsulate a number of predefined states and transition rules, scenarios that trigger contract execution, response actions under specific scenarios, etc. The blockchain can monitor the status of smart contracts in real time, and activate and execute the contract by checking external data sources and confirming that specific trigger conditions are met.
The above is what blockchain technologies the editor has brought to you? All content of the introduction to the core technology of blockchain.

F. The two algorithms in blockchain DNA are

X chain and Y chain.
Two strands are introduced here, (in fact, there are no strands). These two also satisfy the corresponding relationship between DNA double strands.
For the convenience of research, these two chains are recorded as X chain and Y chain respectively. Y chain is responsible for recording transaction information. X is responsible for verifying the correctness of Y chain records. There is a certain relationship between X chain and Y chain.
Define the first block data on the X chain. Stringdata="IloveMaxwell", let M=hash(data, 10), M is the hash value of data represented by decimal number. Search the prime number table to find a prime number P that minimizes.

G. What is blockchain

Blockchain is a term in the field of information technology. Blockchain is an uninterrupted digital ledger of economic transactions that can be programmed to record not just financial transactions butDocument almost anything of value. Simply put, it is a decentralized, distributed database of immutable records that is managed by a cluster of computers but does not belong to any single entity. Blockchain is stored as a database or flat file.