What is blockchain?
The concept of blockchain was first introduced in the whitepaper of Bitcoin, “Bitcoin: A Peer-to-Peer Electronic Cash System” In Bitcoin, blockchain technology emerged as the underlying technology. Later, the blockchain was stripped from experts and existed independently. Blockchain is actually a series of data generated through cryptography.
Blockchain is a decentralized ledger (database), which uses a decentralized and detrusted approach to build a trusted network.
How blockchain works?
Let’s take Bitcoin as an example.
The operation process of the blockchain is the process of bookkeeping, which can be divided into several steps:
The competition of bookkeeping right-solving the POW workload proof function;
Bookkeeping-package the information of the previous block, add new transaction information, and create new blocks;
Broadcast and verification-the bookkeeping node broadcasts the new block random number, and the remaining nodes perform verification;
Successful bookkeeping-After the verification is passed, a time stamp or a new block is created. (Please refer to the process below)
New blocks are sequentially connected to the end of the original block, and the blockchain continues.
Characteristics of blockchain
The characteristics of the blockchain: distributed decentralization, safe, reliable, open and transparent
Blockchain is a distributed database system in which nodes participate. Many nodes form a peer-to-peer network. There is no centralized equipment and management organization. It does not require third-party trust endorsement. Attacking a single node in a decentralized network will not affect the entire network unless more than 50% of the nodes are attacked.
Safe and reliable
The hash function used by the blockchain-an asymmetric encryption protection, and each block advances according to time, making use of time irreversible to prevent tampering.
Open and transparent
Openness and transparency means that every transaction is visible on the entire network. Because the transaction information is contained in the block, every new block created will be broadcast across the network, and all nodes will receive, verify, and update their own blockchain.
What technologies are integrated in the blockchain?
Hash function is a cryptographic hash, y = H (x), its characteristics are:
Enter X with any character length, and you will get Y with fixed length;
The asymmetric encryption function is irreversible. If the value of X is known, the value of y can be easily obtained. However, if the value of y is known, X cannot be obtained by inverse function of the function.
Sensitive to input and strong anti-collision. Two extremely similar but different input values, the hash value obtained after hash calculation is very different, has good collision resistance, and has a high degree of security.
This asymmetric encryption can be used in POW calculations and digital signatures.
Asymmetric encryption technology is used, including a pair of public and private keys. Information encrypted by the public key can only be decrypted by the corresponding private key, and information encrypted by the private key can be decrypted by the corresponding public key. The public key is public and is used by others to pass information to themselves. The private key is only known to you and is used to prove your identity and exercise your rights.
Consensus mechanism is the rule of node bookkeeping for competition in the blockchain system. The blockchain is a decentralized ledger. The transactions generated in it need a node to record and broadcast to the entire network. How to choose one of these nodes? This requires the formulation of a rule and selection according to the rules. This rule is the consensus mechanism, and each participating node must follow the consensus mechanism. Different blockchain systems run different consensus mechanisms. Common consensus machines are POW, POS, and DPOS. The following figure is the workflow of POW.
Development of blockchain
Blockchain 1.0 is composed of digital currency and payment behavior. Its main function is to record transaction information. Take Bitcoin as an example. The main features are chain data block mode, full node sharing, and asymmetric encryption.
Blockchain 2.0 is Turing-complete and can develop smart contracts and DAPPs, such as EtherCat. The use of machine contracts instead of manual operations makes the process more transparent and efficient, represented by Ethereum.
Blockchain 3.0 is to solve the pain points of 2.0. Such as poor performance, congestion. The problem of low TPS, f this problem can be solved, the blockchain technology will be applied on a large scale, representing by EOS, NEO, NAS.
A good partner for blocks-smart contracts, tokens
The blockchain has the characteristics of non-tamperable and decentralized for data. Running smart contracts on the blockchain can ensure that the entire process is open and transparent and cannot be tampered with, while avoiding the influence of centralization factors, and making smart contracts operate efficiently. Similarly, blockchain can provide solid trust, efficient circulation, rich rights and interests and security guarantees for tokens.