Building Your First Blockchain with Go: A Step-by-Step Guide

Step 1: Environment Setup

1. Install Go: Ensure that you have Go installed on your system. Visit the official Go website to download and follow the installation instructions.
2. Set Up Workspace: Create a working directory and set up the GOPATH environment variable if necessary.

Step 2: Create Block Structure

Open your preferred code editor and create a new file named block.go. Add the block structure as follows:

type Block struct {
 Index int
 Timestamp string
 Data string
 PrevHash string
 Hash string
}

Step 3: Hash Function

Add a function to generate the block’s hash:

func calculateHash(block Block) string {
 record := strconv.Itoa(block.Index) + block.Timestamp + block.Data + block.PrevHash
 h := sha256.New()
 h.Write([]byte(record))
 hashed := h.Sum(nil)
 return hex.EncodeToString(hashed)
}

Step 4: Creating a New Block

Add a function to create a new block:

func createBlock(data string, prevBlock Block) Block {
 block := Block{Index: prevBlock.Index + 1, Timestamp: time.Now().String(), Data: data, PrevHash: prevBlock.Hash}
 block.Hash = calculateHash(block)
 return block
}

Step 5: Initialize the Blockchain

Create a function to initialize the blockchain with a genesis block:

func genesisBlock() Block {
 return createBlock("Genesis Block", Block{})
}

Step 6: Adding Blocks to the Blockchain

You can add blocks to a slice and link the blocks together using hashes:

var Blockchain []Block

func addBlock(data string) {
 prevBlock := Blockchain[len(Blockchain)-1]
 newBlock := createBlock(data, prevBlock)
 Blockchain = append(Blockchain, newBlock)
}

Step 7: Main Function

In the main.go file, you can call these functions to build your blockchain:

func main() {
 Blockchain = append(Blockchain, genesisBlock())

 addBlock("Block #1")
 addBlock("Block #2")

 // Print the blockchain
 for _, block := range Blockchain {
  fmt.Printf("Index: %d\n", block.Index)
  fmt.Printf("Timestamp: %s\n", block.Timestamp)
  fmt.Printf("Data: %s\n", block.Data)
  fmt.Printf("Prev. hash: %s\n", block.PrevHash)
  fmt.Printf("Hash: %s\n", block.Hash)
 }
}

Conclusion

By following these steps, you have created a simple blockchain using Go. This is a great foundation to understand how blocks are linked in a chain and how data is stored within the blockchain.

Note that this is a simple example and does not include essential features such as consensus or additional security required in production. However, it’s a good starting point to understand the basic concepts.