Simple Blockchain in Python

This is a basic implementation of a blockchain in Python. It demonstrates the core concepts of a blockchain, including:

• Blocks: Data structures that store transactions and are linked together.
• Proof-of-Work: A mechanism for achieving consensus and adding blocks to the chain.
• Hashing: Used to secure the blockchain and ensure data integrity.

How it Works

1. Block Structure: Each block contains an index, a list of transactions, a timestamp, the hash of the previous block, and a nonce.

2. Genesis Block: The first block in the chain is the genesis block. It is created manually.

3. Proof-of-Work: This implementation uses a simple Proof-of-Work algorithm. To add a new block, a nonce is incremented until the block's hash starts with four zeros.

4. Adding Blocks: New blocks are created with a list of transactions and added to the chain after successful Proof-of-Work.

Files

• blockchain.py: Contains the main code for creating and managing the blockchain.
• block.py: (Not provided) Should contain the Block class definition with the necessary attributes and methods (index, transactions, timestamp, previous hash, nonce, hash calculation).
• transaction.py: (Not provided) Should contain the Transaction class definition to represent transactions.

Usage

1. Implement block.py and transaction.py: Create these files and define the Block and Transaction classes according to the descriptions above.
2. Run blockchain.py: This will create a blockchain with a genesis block and 5 additional blocks.

Limitations

• Simplified Proof-of-Work: The Proof-of-Work algorithm is simplified for demonstration purposes. Real blockchains use more complex algorithms.
• No Networking: This implementation does not include any networking functionality.
• No Difficulty Adjustment: The difficulty of the Proof-of-Work is not dynamically adjusted.
• Basic Transaction Handling: The Transaction class is very basic and does not include any validation or security features.

Disclaimer

This code is for educational purposes only and should not be used in a production environment.

Contributing

Feel free to fork this repository and make improvements. Pull requests are welcome!