Bitcoin'sPoW.py

import hashlib
import time

# text = "Bitcoin mining uses the SHA256 hashing algorithm"
# text_hash = hashlib.sha256(text.encode('utf-8')).hexdigest()

# print(text_hash)

# def findNonce(text):
#     for nonce in range(20):
#         n = text + str(nonce)
#         hash = hashlib.sha256(n.encode('utf-8')).hexdigest()
#         print(f'{nonce} : {hash}')

# findNonce(text)



def proof_of_work(header, difficulty_bits, max_nonce):
    target = 2 ** (256-difficulty_bits) # difficulty target

    for nonce in range(max_nonce):
        to_hash = (str(header) + str(nonce)).encode('utf-8')
        hashed = hashlib.sha256(to_hash).hexdigest()
        if int(hashed, 16) < target: # valid result less than target
            print(f"### SUCCESS ### {nonce}")
            print(f"Nonce: {nonce}\nHashed Result: {hashed}")
            return (hashed, nonce)

    print(f"### FAILED after {nonce} (max_nonce) tries ###")
    return nonce

def solve(nonce, hashed):
    for difficulty_bits in range(32): # difficulty from 0 - 31 bits
        difficulty = 2 ** difficulty_bits
        
        print("### Mining Started...")
        print(f"Difficulty: {difficulty} ({difficulty_bits} bits)")

        start = time.time()
        block = 'Random test block header with transactions' + hashed
        max_nonce = 2 ** 32 # 4 billion
        hashed, nonce = proof_of_work(block, difficulty_bits, max_nonce) # get valid nonce
        end = time.time()

        elapsed_time = end - start
        print(f"Took: {elapsed_time:.4f} seconds")

        if elapsed_time > 0:
            hash_power = float(int(nonce) / elapsed_time) # hashes/second
            print(f"Hashing Power: {hash_power} hashes/second")
            print()

if __name__ == '__main__':
    solve(0, '')