How to solve the problem that the account book of blockchain is
for example, if you are a woman, every time your boyfriend says something disgusting to you or promises to buy something for you, you immediately record it and send it to you and all his friends, classmates, colleagues, as well as various groups and circles of friends, so that he can no longer resist. This is called blockchain
the core advantage of blockchain technology is decentralization, which can realize point-to-point transaction, coordination and cooperation based on decentralized credit in a distributed system without mutual trust by means of data encryption, time stamp, distributed consensus and economic incentive, so as to solve the high cost and low cost of centralized institutions Low efficiency and data storage insecurity provide solutions
the application fields of blockchain include digital currency, token, finance, anti-counterfeiting traceability, privacy protection, supply chain, entertainment, etc. with the popularity of blockchain and bitcoin, many related top domain names have been registered, which has a great impact on the domain name instry.
constructor(index,timestamp,data,previousHash='&# 39;)< br />{
this.index=index;< br />this.timestamp=timestamp;< br />this.data=data;< br />this.previousHash=previousHash;< br />$this.hash=this.calculateHash();< br />}
calculateHash(){
return SHA256(this,index+this.previousHash+this.timestamp+JSON.stringify(this.data)).tostring();< br />}
}
class Blockchain{
constructor(){
this.chain=[this.createGenesisBlock()];<
}
/ / create a generated information block
creategenesis block() {
return new block (0, & quot; 01/01/2019",& quot; Genesis block", 0);
/ / the date is the user's data. In fact, it is the hash value obtained by adding several values together. Here, the information is encrypted and the picture is encrypted. Then the data is still stored in the database, but all the data are hash values. To get this data, you must know the hash value of the previous data block. Then, if the hacker needs to crack all the nodes, the hash value is decrypted, Then all the blocks from the first node to the last node can be decrypted to get the real data. So the security of data stored in the blockchain depends on whether the data is encrypted. If the plaintext is not encrypted, then it is not a blockchain
}
/ / get the last block
getlatesblock() {
return this.chain [this.chain. Length-1]
}
/ / create block
addblock (newblock) {
newblock. Previoushash = this. Getlatesblock(). Hash< br />newBlock.hash=newBlock.calculateHash();< br />this.chain.push(newBlock);< br />}
}
on the other hand, all nodes (computers in short) participating in the network will store one account book, which is updated in real time. Even if one node fails, the blockchain will not be affected.
blockchain is essentially an encryption algorithm, which is based on the principle of hash 256 bit algorithm to achieve information security; The application of modern information will become more and more global and universal. Besides the basic requirements of anti tampering, anti repudiation and trustworthiness, the protection of privacy needs to be strengthened. The blockchain technology is proced because of the development of modern cryptography. The cryptography used today is the result of cryptography 20 years ago, Therefore, in order to apply the blockchain technology to more participation scenarios, especially in the Internet economy, more verification is needed to verify whether the existing encryption technology can meet the demand, and more in-depth integration of cryptographic frontier technology and continuous innovation are needed
as long as we use blockchain to make innovations in accounting methods based on our own mode, it will not affect efficiency and waste computing power, but will shorten the time and improve efficiency.
blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies
the so-called consensus mechanism is a mathematical algorithm to establish trust and obtain interests between different nodes in the blockchain system
in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography
broadly speaking, blockchain technology is a new distributed infrastructure and computing method, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data< Advantages:
1) the algorithm is simple and easy to implement
2) there is no need to exchange additional information between nodes to reach a consensus
3) it takes a lot of cost to destroy the system< Disadvantages:
1) waste of energy
2) it is difficult to shorten the block confirmation time
3) the new blockchain must find a different hash algorithm, otherwise it will face bitcoin attack
4) it is easy to generate bifurcation and needs to wait for multiple confirmations
5) there is no finality, and checkpoint mechanism is needed to make up for it.
Ledger is a book with a certain format and several account pages. Based on the accounting documents, it records all economic business in chronological order and classification, which is what we usually call the ledger. Blockchain represents a unique data record format. Blockchain is "block + Chain". The so-called block is the meaning of data block. Each block is connected by a certain mark to form a chain
Super ledger
hyperledger (Chinese name is super ledger, collectively referred to as hyperledger) is an open source project launched by Linux foundation in 2015 to promote blockchain digital technology and transaction verification. The goal of hyperledger is to enable members to work together to build an open platform to meet the needs of various users from different instries, while greatly simplifying the business process. The founding members of hyperedge include IBM, Intel, Cisco and other large companies. By the end of this book, more than 183 organizations and companies have joined hyperedge, and they are growing rapidly
at the beginning of hyperledger project, Linux foundation has received a number of different code bases, including IBM code base (inspired by Ethereum to a certain extent), Dah (bits of proof bitcoin code base) and sockstream code base (an extension of bitcoin code base). In addition, there are digital asset and ripple contributions. With the development of the instry, a single project has been unable to meet the needs of the business, so hyperledger has graally developed from a single project into a project group. At present, hyperledger is not a specific technology, but a set of blockchain technology frameworks. Up to now, the hyperledger project team contains 9 formal projects and more than 50 moles related to these formal projects
the Xueshuo innovation blockchain Technology Workstation of Lianqiao ecation online is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system
Hyperledger is an open source project launched by Linux foundation in 2015 to promote blockchain digital technology and transaction verification. It is composed of 30 initial enterprise members (including IBM, Accenture, Intel, J.P. Morgan, R3, Dah, DTCC, Fujitsu, Hitachi, swift, Cisco, etc.). The goal is to let members work together to build an open platform, meet various user cases from different instries, and simplify business processes