BlockChain - Secure Distributed Ledger System

A complete, secure, and production-ready blockchain implementation featuring transaction processing, proof-of-work consensus, wallet management, and a distributed peer-to-peer network.

Features

• Complete Blockchain Implementation

  • Proof-of-Work consensus algorithm
  • Dynamic difficulty adjustment
  • Secure transaction validation
  • Mining rewards and fee structures

• Cryptographic Security

  • Strong RSA-3072 based wallet encryption
  • SHA-256 and SHA3-256 hashing for blockchain integrity
  • Digital signatures for transaction verification
  • Password-protected wallet storage

• Distributed Network

  • Peer-to-peer architecture via DHT (Distributed Hash Table)
  • Automatic node discovery and synchronization
  • Chain validation and conflict resolution
  • Automatic bootstrap node detection

• RESTful API

  • Full blockchain management API
  • Wallet creation and management
  • Transaction creation and verification
  • Block mining capabilities
  • Node status monitoring

• Database Persistence

  • PostgreSQL database integration
  • Transaction pool persistence
  • Chain and wallet storage
  • Connection pooling and failure recovery

System Requirements

• Python 3.8+
• PostgreSQL 12+
• Network connectivity for distributed operations
• 2GB+ RAM recommended for mining operations

Installation

Setting up the environment

# Clone the repository
git clone https://github.com/yourusername/BlockChain.git
cd BlockChain

# Create and activate a virtual environment
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install dependencies
pip install -r requirements.txt

Database Setup

1. Create a PostgreSQL database:

CREATE DATABASE blockchain;
CREATE USER blockchain_user WITH PASSWORD 'your_password';
GRANT ALL PRIVILEGES ON DATABASE blockchain TO blockchain_user;

2. Configure the database connection in blockchain/config.py:

DATABASE_CONFIG = {
    'host': 'localhost',
    'port': 5432,
    'database': 'blockchain',
    'user': 'blockchain_user',
    'password': 'your_password'
}

Running the Blockchain

Starting a Bootstrap Node

python -m blockchain.api.app --host 0.0.0.0 --port 5000 --dht-port 6000

This will start a bootstrap node that creates the initial blockchain with a genesis block.

Joining an Existing Network

python -m blockchain.api.app --host 0.0.0.0 --port 5001 --dht-port 6001 --bootstrap 127.0.0.1:6000

Replace 192.168.1.100:6000 with the IP and DHT port of a running bootstrap node.

Basic Usage

Once your node is running, you can interact with the blockchain using the API:

Creating a Wallet

curl http://localhost:5000/wallet/new

This will return a new wallet containing:

• Public address
• Public key
• Private key (store securely!)

Creating a Transaction

curl -X POST http://localhost:5000/transactions/new \
  -H "Content-Type: application/json" \
  -d '{
    "sender": "PUBLIC_KEY_HERE", 
    "recipient": "RECIPIENT_ADDRESS_HERE", 
    "amount": 10,
    "signature": "SIGNATURE_HERE"
  }'

Mining a Block

curl http://localhost:5000/mine?address=YOUR_WALLET_ADDRESS

This will mine a new block with pending transactions and credit mining rewards to the specified address.

Viewing the Blockchain

curl http://localhost:5000/chain

Security Considerations

• Always encrypt and securely store wallet private keys
• Run nodes on secure, firewalled servers
• Consider implementing additional authentication for production use
• Monitor for suspicious transaction patterns
• Regularly backup blockchain database

Documentation

For more detailed documentation, see:

• API Documentation - Complete API reference
• Security Guide - Security features and best practices
• Architecture Overview - System architecture and design
• Advanced Configuration - Advanced configuration options
• Development Guide - Guide for developers extending the system

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contact

For questions or support, please contact [email protected]