def different_context(second_context, plain=1):
cs_1 = CipherScheme()
if second_context == "from_pickle":
cs_2 = pickle.loads(pickle.dumps(cs_1))
elif second_context == "regenerate":
cs_2 = CipherScheme()
elif second_context == "from_cipher":
# steal context from CipherText
pk, _, _, _ = cs_1.generate_keys()
cipher = cs_1.encrypt(pk, plain)
context = cipher._context
cs_2 = CipherScheme()
cs_2.context = context
cs_2._keygen = KeyGenerator(context)
cs_2._evl = Evaluator(context)
elif second_context == "from_encoder":
# steal context from Encoder
pk, _, _, _ = cs_1.generate_keys()
cipher = cs_1.encrypt(pk, plain)
context = cipher._encoder._context
cs_2 = CipherScheme()
cs_2.context = context
cs_2._keygen = KeyGenerator(context)
cs_2._evl = Evaluator(context)
else:
return
pk_1, sk_1, _, _ = cs_1.generate_keys()
pk_2, sk_2, _, _ = cs_2.generate_keys()
cipher_1 = cs_1.encrypt(pk_1, plain)
cipher_2 = cs_2.encrypt(pk_2, plain)
# different CipherSchemes can be used, but not only with keys generated from the original CipherScheme
assert plain == cipher_1.decrypt(sk_1)
assert plain == cipher_2.decrypt(sk_2)
# keys generated by another CipherScheme won't work
assert plain != cipher_1.decrypt(sk_2)
assert plain != cipher_2.decrypt(sk_1)
# keys generated by another CipherScheme won't work, even when using the CipherScheme that generated them
assert plain != cipher_1.decrypt(sk_2)
assert plain != cipher_2.decrypt(sk_1)
def test_relinearize(dbc, expected_noise,
poly_mod=8192, coeff_mod=0, plain_mod=1024, security=128, plain=700, base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, ek, _ = cs.generate_keys(dbc=dbc)
cipher_1 = cs.encrypt(pk, plain, base=base)
cipher_2 = (cipher_1 * cipher_1).relinearize(ek)
assert abs(expected_noise - cipher_2.noise_budget(sk)) <= 2
def test_fresh_noise_budget(coeff_mod, plain_mod, expected_noise,
poly_mod=2048, security=128, plain=1, base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher = cs.encrypt(pk, plain, base=base)
# Noise budget in bits ~ log2(coeff_modulus/plain_modulus)
assert abs(expected_noise - cipher.noise_budget(sk)) <= 1
def test_fresh_size(coeff_mod,
plain_mod,
poly_mod=2048,
security=128,
plain=1,
base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher = cs.encrypt(pk, plain, base=base)
assert cipher.size() == 2
def test_neg_enc_dec(plain,
poly_mod=2048,
coeff_mod=0,
plain_mod=256,
security=128,
base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher_1 = cs.encrypt(pk, plain, base=base)
cipher_2 = -(-cipher_1)
assert abs(plain - cipher_2.decrypt(sk)) <= 0.5
def test_pow_enc_dec(plain,
power,
expected,
poly_mod=8192,
coeff_mod=0,
plain_mod=1024,
security=128,
base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher_1 = cs.encrypt(pk, plain, base=base)
cipher_2 = cipher_1**power
assert abs(expected - cipher_2.decrypt(sk)) <= 0.5
def test_add_plain_enc_dec(plain,
poly_mod=2048,
coeff_mod=0,
plain_mod=256,
security=128,
base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher_1 = cs.encrypt(pk, plain, base=base)
cipher_2 = plain + cipher_1
expected = plain + plain
assert abs(expected - cipher_2.decrypt(sk)) <= 0.5
def test_pow_noise_budget(coeff_mod,
plain_mod,
expected_noise,
poly_mod=4096,
security=128,
plain=1,
base=2,
power=3):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher_1 = cs.encrypt(pk, plain, base=base)
cipher_2 = cipher_1**power
assert abs(expected_noise - cipher_2.noise_budget(sk)) <= 7
def test_neg_noise_budget(coeff_mod,
plain_mod,
expected_noise,
poly_mod=2048,
security=128,
plain=1,
base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher_1 = cs.encrypt(pk, plain, base=base)
cipher_2 = -cipher_1
# Negation consumes ~ zero noise bits
assert abs(cipher_1.noise_budget(sk) - cipher_2.noise_budget(sk)) <= 1
def test_mul_noise_budget(coeff_mod,
plain_mod,
expected_noise,
poly_mod=2048,
security=128,
plain=1,
base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher_1 = cs.encrypt(pk, plain, base=base)
cipher_2 = cipher_1 * cipher_1
# Multiplication consumes ~ half the noise budget
assert abs(cipher_1.noise_budget(sk) -
(2 * cipher_2.noise_budget(sk))) <= 5
def test_same_keygen_different_keys(plain=1):
"""
Repeated called to CipherScheme generate_key() generate matching keys
"""
cs = CipherScheme()
# created from the same KeyGenerator
pk_1, sk_1, _, _ = cs.generate_keys()
pk_2, sk_2, _, _ = cs.generate_keys()
cipher_1 = cs.encrypt(pk_1, plain)
cipher_2 = cs.encrypt(pk_2, plain)
# both sets of keys work
assert plain == cipher_1.decrypt(sk_1)
assert plain == cipher_1.decrypt(sk_2)
assert plain == cipher_2.decrypt(sk_1)
assert plain == cipher_2.decrypt(sk_2)
def test_add_enc_dec(mat_element,
poly_mod=4096,
coeff_mod=0,
plain_mod=40961,
security=128):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
plain = mat_element * np.ones((2, 2048), int)
expected = np.add(plain, plain)
cipher_1 = cs.encrypt(pk, plain)
cipher_2 = cipher_1 + cipher_1
decrypted = cipher_2.decrypt(sk)
assert np.linalg.norm(np.subtract(expected, decrypted),
ord=1) <= 0.5 * poly_mod
def test_mul_by_encoded_plain_enc_dec(plain_1,
plain_2,
poly_mod=2048,
coeff_mod=0,
plain_mod=256,
security=128,
base=2):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
encoded, encoder = Encoder(plain_2, cs.context, base=base)
cipher_1 = cs.encrypt(pk, plain_1, base=base)
cipher_2 = cipher_1 * encoded
expected = plain_1 * plain_2
assert abs(expected - cipher_2.decrypt(sk)) <= 0.5
def test_rotation_enc_dec(shift,
poly_mod=4096,
coeff_mod=0,
plain_mod=40961,
security=128):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, gk = cs.generate_keys()
plain = np.asarray(list(range(poly_mod))).reshape((2, 2048))
expected = np.roll(plain, shift, (0, 1))
cipher_1 = cs.encrypt(pk, plain)
cipher_2 = cipher_1.roll(gk, shift)
decrypted = cipher_2.decrypt(sk)
assert np.linalg.norm(np.subtract(expected, decrypted),
ord=1) <= 0.5 * poly_mod
def test_type_inconsistency(plain_1,
kwargs_1,
plain_2,
kwargs_2,
poly_mod=2048,
coeff_mod=0,
plain_mod=256,
security=128):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
cipher_1 = cs.encrypt(pk, plain_1, **kwargs_1)
cipher_2 = cs.encrypt(pk, plain_2, **kwargs_2)
with pytest.raises(TypeError):
_ = cipher_1 + cipher_2
with pytest.raises(TypeError):
_ = cipher_1 - cipher_2
with pytest.raises(TypeError):
_ = cipher_1 * cipher_2
def test_key_generation(poly_mod, coeff_mod, plain_mod, security):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
assert cs.generate_keys() != cs.generate_keys()
def test_enc_dec(poly_mod, coeff_mod, plain_mod, security, plain, base):
cs = CipherScheme(poly_mod, plain_mod, coeff_mod, security)
pk, sk, _, _ = cs.generate_keys()
assert abs(plain - cs.encrypt(pk, plain, base=base).decrypt(sk)) <= 0.5