def test_shamir_polynomial_compute():
dealer = Dealer(p256, n_participants, s_secrets, access_structures)
dealer.access_group_polynomial_coeffs()
# override coeffs
dealer.d[0][0] = [bytes([0x05]), bytes([0x07])]
coeffs = dealer.get_d_polynomial_coeffs(0, 0)
secret_value = dealer.s_secrets[0]
value = common.shamir_polynomial_compute(bytes([0x01]), coeffs,
secret_value, dealer.p)
assert_equal(value, 12 + s_secrets[0])
value = common.shamir_polynomial_compute(bytes([0x02]), coeffs,
secret_value, dealer.p)
assert_equal(value, 38 + s_secrets[0])
def user_polynomial_value_B(self, i_secret, q_group, participant):
assert(participant in self.access_structures[i_secret][q_group])
print('user_polynomial_value_B for secret %d, group A %d '.format(i_secret, q_group))
participant_id = self.random_id[participant-1]
print('B value for user %d with ID %d'.format(participant, participant_id))
coeffs = self.get_d_polynomial_coeffs(i_secret, q_group)
secret_value = self.s_secrets[i_secret]
# returns int
return common.shamir_polynomial_compute(participant_id, coeffs, secret_value, self.p)
def compute_all_key_shares(self):
self.key_shares = copy.deepcopy(self.access_structures)
print(self.access_structures)
for i, gamma in enumerate(self.access_structures):
for q, A in enumerate(self.access_structures[i]):
for b, Pb in enumerate(self.access_structures[i][q]):
print('secret_value (cipher_key)', self.cipher_keys[i])
secret_value = int.from_bytes(self.cipher_keys[i],
byteorder='big')
self.key_shares[i][q][b] = \
common.shamir_polynomial_compute(self.random_id[b],
self.d[i][q],
secret_value,
self.p)
print(
'Key share = {} for user {} (index {}) and secret {}'.
format(self.key_shares[i][q][b], Pb, b, i))
return self.key_shares