In recent years, # blockchain # technology has become more and more popular. Some people are obsessed with digital currency, and some people are promoting “blockchain+”. Behind the popularity is foam or loneliness. Today we will talk about blockchain in detail. The full text is 3000 words, and the conclusion is at the end.
1、 Origin of blockchain
The concept of blockchain was first derived from Bitcoin.
Bitcoin was first proposed in 2008 by a person named Satoshi Nakamoto, who is very mysterious and has no accurate information about him. Soon after it was proposed, Bitcoin was born.
The core technology of Bitcoin and other digital currencies is called blockchain technology. Blockchain is a data structure or data storage method in information technology. It innovatively combines cryptography, peer-to-peer (P2P) network, distributed deployment and other technologies, which can be called an epoch-making concept.
2、 Overview of blockchain technology
1.1 Blockchain structure
As shown in the figure below:
Blockchain structure
A typical blockchain is composed of a series of blocks, which are composed of pre hash, block time and records.
The preview, similar to the seal on the file, is used to ensure that the contents of the block are not changed. Each block of the blockchain forms a hash value (i.e. seal) through computer operation and stores it in the preamble of the second block. This hash value is unique. If the content of the block changes, the hash value will also change. This ensures that the content of the block cannot be changed. The ingenuity of blockchain design lies in that the latter block stores the hash value of the previous block, and the blocks are linked with each other to form a blockchain.
Blocking time is used to record the time when a block is formed.
Records are used to record all the information that needs to be saved. They can be transaction information, a sentence or other information.
1.2 Operation mechanism
In addition to sophisticated structural design, the blockchain also needs a rigorous mechanism to ensure the stable operation of the blockchain, which is also the core innovation of the blockchain and solves the trust problem.
Blockchain operation mechanism
The blockchain adopts a distributed storage architecture, and the data of the blockchain is completely stored on all nodes of the blockchain network. The figurative metaphor is that I copied countless copies of a file and saved them in different parts of the world. Anyone who wants to tamper with the records must modify the records of each node. When there are enough nodes, such tampering cannot be achieved. This is the secret of blockchain anti tampering.
1.3 Mining
As mentioned earlier, blockchain is linked from block to block. How is the latter block generated?
mining
If you want to add records to the blockchain, you must meet the requirements of the blockchain and find blocks that meet the standards. This process is commonly known as mining. Because there are many people mining, in order to solve the block chain synchronization and forgery chain attacks, the mining difficulty must be increased. The method to increase the difficulty is called the POW (Proof of Work) algorithm. The specific algorithm that is interested can be searched. This algorithm turns a simple operation into hundreds of millions of repeated operations, greatly increasing the difficulty of operation.
Mining is a process of repetition and luck. The miner who first digs this block will inform all nodes and put this block on the chain. The miner will be rewarded (i.e. various digital currencies), and all miners will start to calculate the next block again. As video cards are very good at repeated and simple calculations, they are loved by absenteeism, leading to the price of high-end video cards rising.
Of course, it should be noted here that the POW algorithm, even the mining process, is not necessary. The POW algorithm is a consensus algorithm, and other consensus algorithms can also be used in the blockchain.
1.4 Relationship between Bitcoin (Digital Currency) and Blockchain
Bitcoin and other digital currencies are applications based on the blockchain technology. Bitcoin has formulated a set of rules. Every block calculated, a certain amount of bitcoin is obtained. Bitcoin and its transaction information are recorded in each block. Generally speaking, Bitcoin is a record on the blockchain.
1.5 Blockchain technology summary
After the above analysis, we summarize several characteristics of the blockchain:
First, blockchain can be used to store data or information;
Second, the information stored in the blockchain can hardly be changed (unless the blockHash is modified one by one);
Third, each node of the blockchain is equal, and there is no difference between the control end and the client, which is commonly referred to as decentralization.
