MiniBTC

A lightweight Bitcoin implementation from scratch in Go, inspired by Bitcoin and Decred protocols.

🚀 Overview

MiniBTC is a educational cryptocurrency implementation that demonstrates core blockchain concepts including proof-of-work consensus, UTXO model, digital signatures, and peer-to-peer networking. Built entirely in Go without external blockchain libraries, this project showcases fundamental cryptographic and distributed systems principles.

✨ Features

• Blockchain Core

  • Proof-of-Work consensus mechanism
  • UTXO (Unspent Transaction Output) model
  • Block validation and chain reorganization
  • Merkle tree transaction verification

• Cryptography

  • ECDSA digital signatures
  • SHA-256 hashing
  • Address generation and validation
  • Transaction signing and verification

• Networking

  • Peer-to-peer protocol implementation
  • Node discovery and connection management
  • Block and transaction propagation
  • Network message handling

• Transaction System

  • Input/output transaction model
  • Transaction fees and validation
  • Multi-signature support foundation
  • Mempool management

🛠️ Installation

# Clone the repository
git clone https://github.com/Fantasim/minibtc.git
cd minibtc

# Install dependencies
go mod tidy

# Build the project
go build -o minibtc ./cmd/minibtc

🚀 Quick Start

Running a Node

# Start a mining node
./minibtc node --mine

# Start a regular node
./minibtc node

# Connect to specific peers
./minibtc node --peers=127.0.0.1:8333,192.168.1.100:8333

Wallet Operations

# Create a new wallet
./minibtc wallet create

# Generate a new address
./minibtc wallet address

# Check balance
./minibtc wallet balance

# Send transaction
./minibtc wallet send --to=<address> --amount=<amount>

Mining

# Start mining
./minibtc mine --address=<mining-address>

# Set mining difficulty
./minibtc mine --difficulty=4

🔧 Configuration

Create a config.json file:

{
  "network": {
    "port": 8333,
    "max_peers": 8,
    "protocol_version": 1
  },
  "mining": {
    "difficulty": 4,
    "block_time": 600
  },
  "wallet": {
    "data_dir": "./wallet_data"
  }
}

📊 Technical Specifications

Feature	Implementation
Hashing Algorithm	SHA-256
Signature Scheme	ECDSA (secp256k1)
Consensus	Proof-of-Work
Block Time	~10 minutes (configurable)
Max Block Size	1MB
Address Format	Base58Check encoded

🧪 Testing

# Run all tests
go test ./...

# Run with coverage
go test -cover ./...

# Run specific package tests
go test ./blockchain/...

Key Concepts

Blockchain Fundamentals

• Block Structure: Headers, transactions, merkle roots
• Chain Validation: Longest chain rule, orphan handling
• Difficulty Adjustment: Dynamic mining difficulty

Cryptographic Security

• Digital Signatures: Transaction authorization
• Hash Functions: Block linking and proof-of-work
• Key Management: Public/private key pairs

Network Protocol

• Message Types: Block, transaction, ping/pong
• Peer Discovery: Bootstrap nodes, peer exchange
• Consensus: Block propagation and validation

Transaction Model

• UTXO Set: Unspent transaction tracking
• Script System: Basic transaction scripting
• Fee Market: Transaction prioritization

🔍 Code Structure Highlights

// Example: Block structure
type Block struct {
    Header       BlockHeader
    Transactions []Transaction
}

type BlockHeader struct {
    PrevHash     [32]byte
    MerkleRoot   [32]byte
    Timestamp    int64
    Difficulty   uint32
    Nonce        uint32
}

🚧 Development Status

• ✅ Core blockchain functionality
• ✅ Basic wallet operations
• ✅ Proof-of-work mining
• ✅ P2P networking
• 🔄 Advanced scripting

🙏 Acknowledgments

• Bitcoin: Original cryptocurrency design and implementation
• Decred: Improved consensus mechanisms and governance
• Go Community: Excellent tooling and libraries