Muntaha

[haseebas0004]

import hashlib
import datetime

class Block:
def init(self, timestamp, data, previous_hash=''):
self.timestamp = timestamp
self.data = data
self.previous_hash = previous_hash
self.hash = self.calculate_hash()
self.nonce = 0 # For proof-of-work

def calculate_hash(self):
    data_string = str(self.timestamp) + str(self.data) + str(self.previous_hash) + str(self.nonce)
    return hashlib.sha256(data_string.encode()).hexdigest()

def mine_block(self, difficulty):
    target = "0" * difficulty
    while self.hash[:difficulty] != target:
        self.nonce += 1
        self.hash = self.calculate_hash()
    print("Block Mined!!! Hash:", self.hash)

class Blockchain:
def init(self):
self.chain = [self.create_genesis_block()]
self.difficulty = 4 # Adjust difficulty for mining time

def create_genesis_block(self):
    return Block(datetime.datetime.now(), "Genesis Block", "0")

def add_block(self, data):
    previous_block = self.chain[-1]
    new_block = Block(datetime.datetime.now(), data, previous_block.hash)
    new_block.mine_block(self.difficulty)
    self.chain.append(new_block)

def is_chain_valid(self):
    for i in range(1, len(self.chain)):
        current_block = self.chain[i]
        previous_block = self.chain[i-1]

        if current_block.hash != current_block.calculate_hash():
            return False

        if current_block.previous_hash != previous_block.hash:
            return False

    return True

Example Usage:

my_blockchain = Blockchain()
my_blockchain.add_block("Transaction 1: Send 10 BTC to Alice")
my_blockchain.add_block("Transaction 2: Send 5 BTC to Bob")
my_blockchain.add_block("Transaction 3: Send 1 BTC to Charlie")

print("Blockchain Valid?", my_blockchain.is_chain_valid())

Print the blockchain (for demonstration - in real life, this would be a distributed ledger)

for block in my_blockchain.chain:
print("Timestamp:", block.timestamp)
print("Data:", block.data)
print("Hash:", block.hash)
print("Previous Hash:", block.previous_hash)
print("---------------------")

Example of tampering (making the chain invalid)

my_blockchain.chain[1].data = "Tampered Data"

print("Blockchain Valid after tampering?", my_blockchain.is_chain_valid())good luck