IS Lab

IS/Lab/Lab7/HomomorphicRSA.py

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+from Crypto.PublicKey import RSA
+from Crypto.Util.number import bytes_to_long, long_to_bytes
+
+
+def generate_keys():
+    key = RSA.generate(2048)
+    return key
+
+
+def encrypt(message, public_key):
+    n = public_key.n
+    e = public_key.e
+    ciphertext = pow(message, e, n)
+    return ciphertext
+
+
+def decrypt(ciphertext, private_key):
+    n = private_key.n
+    d = private_key.d
+    plaintext = pow(ciphertext, d, n)
+    return plaintext
+
+
+# Generate keys
+key = generate_keys()
+public_key = key.publickey()
+private_key = key
+
+# Original values
+m1 = 7
+m2 = 3
+
+# Encrypt
+c1 = encrypt(m1, public_key)
+c2 = encrypt(m2, public_key)
+print(f"Ciphertext 1: {c1}")
+print(f"Ciphertext 2: {c2}")
+
+# Homomorphic multiplication
+c_product = (c1 * c2) % public_key.n
+print(f"Encrypted product: {c_product}")
+
+# Decrypt result
+decrypted_product = decrypt(c_product, private_key)
+print(f"Decrypted product: {decrypted_product}")
+
+# Verify
+expected_product = m1 * m2
+print(f"Expected product: {expected_product}")
+print(f"Match: {decrypted_product == expected_product}")