blockchain/simple_proof_of_work.py added

Author: mapaba79

blockchain/simple_proof_of_work.py

@@ -0,0 +1,35 @@
+import hashlib
+
+def proof_of_work(block_number: int, transactions: str, previous_hash: str, 
+                  difficulty: int) -> tuple[int, str]:
+    """
+    Finds a nonce such that the hash of the block 
+    starts with a specfic number of zeros
+    """
+    prefix = '0' * difficulty
+    nonce = 0
+
+    while True:
+        # Create a single string representing all block data
+        text = str(block_number) + transactions + previous_hash + str(nonce)
+        
+        # Calculate the SHA-256
+        current_hash = hashlib.sha256(text.encode()).hexdigest()
+
+        #  Check if the hash meets the difficulty requirement
+        if current_hash.startswith(prefix):
+            return nonce, current_hash
+
+        nonce += 1
+
+if __name__ == "__main__":
+    # Example usage:
+    example_tx = "Alice sends 1 BTC to Bob"
+    prev_h = "00000abcdef1234567890"
+    diff = 5 # Increase to see get much slower
+
+    print(f"Mining block... (Difficulty: {diff})")
+    nonce,hash_found = proof_of_work(1, example_tx, prev_h, diff)
+
+    print(f"Success! Nonce: {nonce}")
+    print(f"Hash: {hash_found}")