def test_simple_elgamal_encryption_decryption(self):
nonce = ONE_MOD_Q
secret_key = TWO_MOD_Q
keypair = get_optional(elgamal_keypair_from_secret(secret_key))
public_key = keypair.public_key
self.assertLess(public_key.to_int(), P)
elem = g_pow_p(ZERO_MOD_Q)
self.assertEqual(elem, ONE_MOD_P) # g^0 == 1
ciphertext = get_optional(elgamal_encrypt(0, nonce,
keypair.public_key))
self.assertEqual(G, ciphertext.alpha.to_int())
self.assertEqual(
pow(ciphertext.alpha.to_int(), secret_key.to_int(), P),
pow(public_key.to_int(), nonce.to_int(), P),
)
self.assertEqual(
ciphertext.beta.to_int(),
pow(public_key.to_int(), nonce.to_int(), P),
)
plaintext = ciphertext.decrypt(keypair.secret_key)
self.assertEqual(0, plaintext)
def test_elgamal_generated_keypairs_are_within_range(
self, keypair: ElGamalKeyPair):
self.assertLess(keypair.public_key.to_int(), P)
self.assertLess(keypair.secret_key.to_int(), G)
self.assertEqual(g_pow_p(keypair.secret_key), keypair.public_key)
def test_cached_one(self):
plaintext = int_to_q_unchecked(1)
ciphertext = g_pow_p(plaintext)
plaintext_again = discrete_log(ciphertext)
self.assertEqual(1, plaintext_again)
def test_simple_powers(self):
gp = int_to_p(G)
self.assertEqual(gp, g_pow_p(ONE_MOD_Q))
self.assertEqual(ONE_MOD_P, g_pow_p(ZERO_MOD_Q))
def test_cached(self, exp: int):
plaintext = get_optional(int_to_q(exp))
exp_plaintext = g_pow_p(plaintext)
plaintext_again = discrete_log(exp_plaintext)
self.assertEqual(exp, plaintext_again)
