Merge pull request #21 from yusufidimaina9989/master

Add rabin_Sig (python)

py/rabin2.py

@@ -0,0 +1,84 @@
+import random
+import hashlib
+
+
+class RabinSecurityLevel:
+    def __init__(self, level):
+        self.level = level
+
+    def calculate_bits(self):
+        return self.level * 512
+
+
+class RabinPubKey:
+    def __init__(self, n):
+        self.n = n
+
+
+class RabinSig:
+    def __init__(self, s, u):
+        self.s = s
+        self.u = u
+
+
+def generate_rabin_key_pair(security_level):
+
+    # Generate two large prime numbers.
+    p = random.randint(2**security_level, 2**(security_level+1))
+    q = random.randint(2**security_level, 2**(security_level+1))
+
+    # Compute the public key.
+    n = p * q
+
+    # Compute the private key.
+    phi = (p - 1) * (q - 1)
+    e = 65537
+    d = pow(e, -1, phi)
+
+    return RabinPubKey(n), d
+
+
+def sign_rabin(msg, priv_key, pub_key):
+
+    # Compute the hash of the message.
+    h = hashlib.sha256(msg).digest()
+
+    # Compute the signature.
+    s = pow(h, priv_key, pub_key.n)
+
+    # Pad the signature with random bytes.
+    u = random.randbytes(security_level.calculate_bits())
+
+    return RabinSig(s, u)
+
+
+def verify_rabin(msg, sig, pub_key):
+
+    # Compute the hash of the message.
+    h = hashlib.sha256(msg).digest()
+
+    # Compute the signature.
+    s2 = pow(sig.s, 2, pub_key.n)
+
+    # Check if the signature is valid.
+    return s2 == h
+
+
+if __name__ == '__main__':
+    # Create a new RabinSecurityLevel object with the default security level.
+    security_level = RabinSecurityLevel(6)
+
+    # Generate a public and private key pair.
+    pub_key, priv_key = generate_rabin_key_pair(security_level)
+
+    # Sign a message.
+    msg = b'Hello, sCrypt!'
+    sig = sign_rabin(msg, priv_key, pub_key)
+
+    # Verify the signature.
+    is_valid = verify_rabin(msg, sig, pub_key)
+
+    if is_valid:
+        print('Signature is valid.')
+    else:
+        print('Signature is invalid.')