Blockchain

 

Blockchain System: A Comprehensive Guide to Building Your Own

In this blog post, we'll explore a basic implementation of a blockchain system, complete with functionalities for managing clients, transactions, blocks, and mining.

Features of Our Blockchain System

Our blockchain system includes the following key features:

• Client Management: Create and manage clients with RSA key pairs for secure transactions.

• Transaction Handling: Create and verify transactions with digital signatures.

• Block Management: Create, add, and manage blocks in the blockchain.

• Mining: Implement a proof-of-work algorithm for mining blocks.

• Parallel Mining: Utilize multiple miners to mine blocks in parallel.

Dependencies

Before diving into the code, ensure you have the following Python libraries installed:

• logging

• time

• typing

• cupy

• hashlib

• pycryptodome

• binascii

• collections

• datetime

• concurrent.futures

Additionally, CUDA 12.\ or later* must be installed for GPU-related functionalities. Install the dependencies using the following command:

bash

pip install cupy pycryptodome Crypto cupy-cuda12x pycuda

Classes and Methods

Let's break down the core components of our blockchain system:

Client

Attributes:

• username: The username of the client.

• password: The hashed password of the client.

• role: The role of the client (default is "user").

• amount: The amount of coins the client has (default is 0).

Methods:

• __init__: Initializes a new client with a username, password, and role.

• identity: Returns the public key of the client in hexadecimal format.

• userName: Returns the username of the client.

• role: Returns the role of the client.

Transaction

Attributes:

• sender: The sender of the transaction (a Client object or "Genesis").

• recipient: The recipient of the transaction.

• value: The value of the transaction.

• time: The timestamp of the transaction.

Methods:

• __init__: Initializes a new transaction with a sender, recipient, and value.

• to_dict: Converts the transaction to a dictionary.

• sign_transaction: Signs the transaction with the sender's private key.

Block

Attributes:

• verified_transactions: A list of verified transactions.

• previous_block_hash: The hash of the previous block.

• _hash: The hash of the current block.

• Nonce: The nonce for the proof-of-work.

• timestamp: The timestamp of the block.

Methods:

• __init__: Initializes a new block with the hash of the previous block.

• add_transaction: Adds a transaction to the block.

• gpu_sha256: Computes the SHA-256 hash of the data using GPU.

• compute_hash: Computes the hash of the block.

Blockchain

Attributes:

• _chain_list: The list of blocks in the blockchain.

• current_transactions: The list of current transactions.

• current_rewarded_transactions: The list of current rewarded transactions.

• nodes: The set of nodes in the network.

• clients: A dictionary of clients.

• miners: A dictionary of miners.

Methods:

• __init__: Initializes a new blockchain.

• get_chain: Returns the list of blocks in the blockchain.

• reward: Returns the reward for mining a block.

• create_genesis_block: Creates the genesis block.

• authenticate_client: Authenticates a client with username and password.

• add_client: Adds a new client.

• verify_transaction_signature: Verifies the signature of a transaction.

• validate_transaction: Validates a transaction.

• create_transaction: Creates a new transaction.

• add_block: Adds a block to the blockchain.

• create_block: Creates a new block.

• proof_of_work: Performs the proof-of-work algorithm for mining a block.

• process_reward: Processes the reward for mining a block.

• buy_coins: Buys coins for a client.

• check_client_has_coin: Checks if a client has coins.

• mine_block: Mines a block.

• parallel_mine_block: Mines blocks in parallel using multiple miners.

Usage

Create a Blockchain Instance

bash

blockchain = Blockchain()

Add Clients

bash

blockchain.add_client("username1", "password1")
blockchain.add_client("username2", "password2", miner=True)

Create and Authenticate Transactions

bash

sender = blockchain.authenticate_client("username1", "password1")
transaction = blockchain.create_transaction(sender, "recipient_identity", 10)

Mine Blocks

bash

miner = blockchain.miners["miner_identity"]
blockchain.mine_block(miner)

Check Blockchain Status

bash

print(blockchain.get_chain)

License

This project is not licensed.

Here is the github reference: yuvarajdr/Blockchain