Simple Blockchain Project

Overview

This project demonstrates a very simple blockchain implementation. The blockchain is represented using JSON files, and it includes basic functionalities such as adding transactions, checking balances, and mining blocks. I made this project to help me better understand how blockchains work.

Specifications

Components

1. Ledger Creation Script (ledgers.py)

   • Continuously creates new ledgers every minute.
   • Marks the latest ledger with "islatest": true.
   • Saves the ledgers to a JSON file (ledgers.json).

2. Transaction Script (transactions.py)

   • Allows users to add transactions to the latest ledger.
   • Provides functionality to check the balance of a user by summing the amounts received and sent.
   • Updates the JSON file (ledgers.json) with new transactions.

3. Mining Script (mining.py)

   • Continuously checks for ledgers that are not hashed and not marked as the latest.
   • Mines these ledgers by finding a stamp that generates a valid hash with a certain difficulty (e.g., leading zeros).
   • Updates the JSON file (ledgers.json) with the stamp and hash values.

4. Blockchain Explorer (data_grabber.py, templates/index.html)

   • Provides a web interface to view the blockchain data.
   • Displays blocks, transactions, and user balances.
   • Uses Flask and Socket.IO to serve the web interface and update data in real-time.

JSON Structure

The ledgers are stored in a JSON file (ledgers.json) with the following structure:

{
    "ledger1": [
        {
            "date": "2024-07-24 12:00:00",
            "hash": "",
            "stamp": "",
            "islatest": true
        },
        ...
    ],
    ...
}

Mining Algorithm

The mining algorithm works as follows:

1. Combine the content of the ledger, the hash of the previous ledger, and a stamp.
2. Hash the combined string using MD5.
3. Check if the hash meets the difficulty requirement (e.g., starts with 5 zeros).
4. If the hash is valid, store the stamp and hash in the JSON file.

Usage

Ledger Creation Script

To run the ledger creation script:

python ledgers.py

This script will continuously create new ledgers every minute and save them to ledgers.json.

Transaction Script

To run the transaction script:

python transactions.py

This script allows users to check their balance or make transactions.

Mining Script

To run the mining script:

python mining.py

This script continuously mines new ledgers that are ready to be mined and updates the ledgers.json file with the results.

Blockchain Explorer

To run the blockchain explorer:

python data_grabber.py

This script starts a Flask web server and serves the blockchain explorer interface at http://localhost:5000.

Conclusion

This simple blockchain project provides a basic implementation of a blockchain using Python and JSON files. It covers the fundamental aspects of blockchain technology, including ledger creation, transaction handling, and mining. This project is a great starting point for anyone looking to learn about blockchains and their underlying principles.

Changelog

v1.1

• Added a blockchain explorer with a web interface using Flask and Socket.IO.
• Displays blocks, transactions, and user balances in real-time.
• Added data_grabber.py and templates/index.html for the web interface.