Is the data of blockchain permanently stored

1. In short, the data of the blockchain is formally stored in the blockchain through the formula algorithm process of the block. All nodes in the whole network express that they accept the block, and the way to express acceptance is to make the random hash value of the block the latest block hash value. Xingqun manufacturing will be extended based on the blockchain.

2. const SHA256 = require(crypto-js/SHA256);< br />class Block{
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 />}
}

3. The registered digital assets are stored in the blockchain. In essence, the blockchain is a decentralized distributed ledger database, which is a series of data blocks generated by the use of cryptography, and its characteristics are unchangeable and unforgeable. Similar to the digital asset registration business done by gold owners, it uses blockchain to store digital assets. In this way, every registration record of the platform can be traced, forged and tampered with. It is precisely because of this characteristic that when users have ownership disputes, such data can have credibility and can be provided to administrative departments as the basis for law enforcement.

4. Encryption code. Every few minutes, a new block is generated, which stores different information and consists of different passwords (double keys).

5. Hello, of course.
blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain is an important concept of bitcoin. It is essentially a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of information about bitcoin network transactions, Used to verify the validity of its information (anti-counterfeiting) and generate the next block. In fact, the original English version of bitcoin white paper [1] does not use the word blockchain, but uses the word chain of blocks. In the earliest Chinese translation of bitcoin white paper [2], chain of blocks was translated into blockchain. This is the earliest time when the Chinese word "blockchain" appeared.

6. Big data and blockchain are two independent things, which do not have to be used
in fact, only high-level security data can be used for blockchain development, and most companies do not have this requirement. It can be understood that there are so many companies in the world, only a small part needs to use big data technology, and a smaller part needs to use blockchain technology. These two parts can intersect but do not include
for companies that normally use big data, there are non relational databases like HBase, mongodb, hive, Mr, spark and so on in terms of storage and processing, which have nothing to do with blockchain.

7. DGC is really unreliable. It's been 20 days since the withdrawal. I think it's really unreliable. Sorry to die

8. The analysis of jinwowo network technology is as follows:
the most outstanding advantage of blockchain is that once the record is written, it is sent to multiple distributed blocks, which makes it easy to be deployed on different nodes on the network. At the same time, each record contains its unique hash value signature, which makes them unable to be tampered with
through the blockchain network, the distributed ledger can record more abundant and comprehensive transaction history, rather than only specific users can see it through the internal system or blacklist as before.

9. The core advantage of blockchain is decentralization. Through the use of encryption algorithm, tree structure and consensus mechanism, trust relationship is established in decentralized distributed network, data distributed multi node encrypted storage is realized, and an open, transparent, tamperable, verifiable and traceable technology system is created, so that each node can store certificates synchronously and supervise together, It can effectively solve the problems of poor reliability and low security in the centralized mode
in Internet cases, electronic evidence is difficult to keep, collect and notarize. By using blockchain technology, easyprovision can solve the whole link trustworthiness problems of electronic evidence, such as generation, storage, notarization and evidence proof; After being linked, each judicial node in the security chain is used to ensure the data's trustworthiness and security; In litigation, evidence goes directly to the Internet court to improve the efficiency of rights protection.