What is blockchain technology?

The concept of blockchain can be said to be very popular. At the online financial summit, no one said that blockchain technology is outdated. What is blockchain technology?

Blockchain technology can be an open classification (anyone can see it) or an authorized network (only authorized people can see it), which solves the challenge of supply chain. Because it is an unchangeable record, it is shared among network participants and updated in real time.

Blockchain technology-data layer: designing the data structure of account books

Core technology 1, block _ _ chain:

Technically, a block is a data structure that records transactions and reflects the capital flow of transactions. The transaction blocks that have arrived in the system form the main chain, and all nodes participating in the calculation record the main chain or a part of the main chain.

Each block consists of a block header and a block, and the block is only responsible for recording all the previous transaction information, mainly including the number and details of transactions. The block header includes the current version number, the address of the previous block, the time stamp (recording the time when the block was generated, accurate to the second), the random number (recording the answer value of the related mathematical problem to decrypt the block), the target hash value of the current block, the root value of Merkle number and other information. Structurally, the blockchain is very large.

Core technology II. Hash function:

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Hash function can convert data of any length in hash algorithm into code of fixed length. The principle is a one-way hash function based on cryptography, which is easy to verify, but difficult to interpret. The industry usually expresses it in the form of y=hash(x). This hash function realizes the hash value y of x. 。

Commonly used hash algorithms are MD5, SHA- 1, SHA-256, SHA-384, SHA-5 12, etc. Taking SHA256 algorithm as an example, any data input into SHA256 will get a 256-bit hash value. Its characteristic is that the same data input will get the same result. The input data has changed slightly. 1 becomes 0) will get completely different results. In this way, the forward calculation (data calculation corresponding hash value) is very simple, but the reverse calculation is extremely difficult, which is considered impossible under the current scientific and technological conditions.

Core technology 3, Merkle tree:

Merkle tree is a hash binary tree, which can quickly verify the integrity of large-scale data. In the blockchain network, Merkle_ Palace is where employees are paid _ Scandium is where employees are paid _ Where employees are paid _ Where employees are paid _ Where employees are paid _ Where employees are paid. Trees.

Core technology 4. Asymmetric encryption algorithm:

Asymmetric encryption algorithm is a key security method, which requires a key and a key. The public key and the private key are a pair. If the data is encrypted with the public key, it can only be decrypted with the corresponding private key to get the corresponding data value. If the data is signed with a private key, then the signature can only be verified with the corresponding public key, and the sender of the verification information is the owner of the private key.

Because encryption and decryption use two different keys, this algorithm is called asymmetric encryption algorithm, while symmetric encryption uses the same key during encryption and decryption.

Blockchain Technology —— Network Layer: Centralization of Toll Nodes

Core technology 5. P2P network:

Peer-to-peer network (P2P network), also known as peer-to-peer technology, is an Internet system without a central server to exchange information with users. Different from the central network system with a central server, each client of P2P network is a node and also has the function of a server. Domestic Thunder software adopts P2P technology. P2P network has the characteristics of centralization and reinforcement.

Blockchain technology-* * knowledge layer: distributing the task load of charging nodes