Golang implements blockchain

Currently, with the prosperity of the virtual currency market and the development of blockchain technology, blockchain has become a topic of great concern. In terms of characteristics, blockchain is a technology used to maintain distributed databases. Its unique decentralization and credibility can effectively protect the authenticity of data. Bitcoin, the most popular virtual currency at present, is one of the financial tools that applies blockchain technology. Against this background, this article will discuss how to use golang to implement a simple blockchain example.

1. Basic knowledge of blockchain

Before we start to introduce how to use golang to implement a blockchain, we must first understand some basic concepts:

1. What is a block?

A block is a data structure that contains multiple data, such as transaction information, timestamps, block headers, etc.; at the same time, it also saves the hash value of the previous block, forming An immutable linked list structure.

2. What is hashing?

Hashing refers to a method of compressing a message of any length into a fixed-length message digest. Hash functions can convert data of any size into smaller data sets and are commonly used in cryptography and data integrity verification. In a blockchain, a hash function is used to link the previous block to the next block, thus forming a chain structure.

3. What is proof of work?

In the blockchain, in order to better maintain the authenticity and credibility of the data, a method called workload proof is adopted. The main idea is to add a random number mechanism that is difficult to calculate in the blockchain, so that miners need to go through certain calculations to obtain the "right of proof" and then obtain Bitcoin rewards. This mechanism effectively avoids the possibility of tampering.

4. What is Bitcoin?

Bitcoin is a virtual currency created in 2009 by Satoshi Nakamoto. It is based on blockchain technology and adopts the characteristics of decentralization, anonymity and immutability. Unlike traditional currencies, Bitcoin has a fixed total supply and the supply will gradually decrease in the future. Therefore, it has strong scarcity and has become an area that currently attracts a large number of investors, miners and programmers.

2. How to implement a simple blockchain in golang?

After understanding the basic knowledge of blockchain, we can start to introduce how to use golang to write a simple blockchain.

First, we need to define the block structure, which includes member variables such as transaction information, timestamp and hash:

type Block struct {

Timestamp     int64          // 时间戳
Data          []byte         // 交易信息
PrevBlockHash []byte         // 前一个区块的哈希
Hash          []byte         // 当前区块的哈希
Nonce         uint32         // 工作量证明计数器

}

Based on this, we can define a blockchain structure, which includes a linked list of all blocks and some other member variables:

type Blockchain struct {

blocks []*Block             // 区块链
difficulty uint32           // 工作量证明难度

}

Then, we need to initialize the blockchain, generate the genesis block and add it to the blockchain structure:

func NewBlockchain() *Blockchain {

genesisBlock := NewGenesisBlock()
return &Blockchain{[]*Block{genesisBlock}, 1}

}

func NewGenesisBlock() *Block {

return NewBlock("Genesis Block", []byte{})

}

Next, we need to perform proof-of-work calculations to obtain the miner’s verification rights. During specific implementation, we require that the block hash must meet a certain number of "leading 0s" to be considered a successful calculation. At the same time, since the hash in the blockchain is referenced by the hash of the previous block, every time a new block is added, the hash value must be updated, otherwise the entire chain will become invalid.

func (b *Block) HashTransactions() []byte {

var txHashes [][]byte
var txHash [32]byte

for _, tx := range b.Transactions {
    txHashes = append(txHashes, tx.ID)
}

txHash = sha256.Sum256(bytes.Join(txHashes, []byte{}))
return txHash[:]

}

func NewBlock(data string, prevBlockHash []byte) *Block {

block := &Block{time.Now().Unix(), []byte(data), prevBlockHash, []byte{}}
pow := NewProofOfWork(block)
nonce, hash := pow.Run()

block.Hash = hash[:]
block.Nonce = nonce

return block

}

func (pow *ProofOfWork) Run() (uint32, []byte) {

var hashInt big.Int
var hash [32]byte
nonce := uint32(0)

for nonce < maxNonce {
    data := pow.prepareData(nonce)
    hash = sha256.Sum256(data)

    hashInt.SetBytes(hash[:])

    if hashInt.Cmp(pow.target) == -1 {
        break
    } else {
        nonce++
    }
}

return nonce, hash[:]

}

Finally, we can define the related The RPC protocol is used to perform command interactions on the blockchain, such as adding a new block, querying blockchain information, etc. The purpose of this article is not to introduce the details of RPC implementation, so I won’t go into details.

3. Summary

As one of the technology fields that have attracted much attention in recent years, blockchain has broad application prospects in many fields such as finance and the Internet of Things. In this process, golang has also become an excellent choice for blockchain implementation with its unique high performance and coroutine support. This article introduces the basic concepts of blockchain and the method of using golang to implement blockchain, hoping that readers can better understand and apply blockchain technology.

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