def test_provide_id():
dealer = Dealer(p256, n_participants, s_secrets, access_structures)
id_list = common.provide_id(n_participants, dealer.hash_len, dealer.p)
# check the length of the list
assert_equal(len(id_list), n_participants)
# check the type of object in the list
assert_equal(isinstance(id_list[0], bytes), True)
def split_secrets(self):
""" Split secret in one step """
self.random_id = common.provide_id(self.n, self.hash_len, self.p)
self.master_shares_x = self.choose_distinct_master_shares_x()
self.access_group_polynomial_coeffs()
self.compute_all_pseudo_shares()
self.compute_all_public_shares_M()
return self.pseudo_shares
def split_secrets(self):
""" Split secret in one step with Lin-Yeh algorithm """
self.random_id = common.provide_id(self.n, self.hash_len, self.p)
self.master_shares_x = common.list_of_random_in_modulo_p(
self.n, self.hash_len, self.p)
self.access_group_polynomial_coeffs()
self.compute_all_pseudo_shares()
self.compute_all_public_shares_M()
return self.pseudo_shares
def split_secrets(self):
""" High-level interface function.
Use Shamir's scheme to share the keys used
to encrypt secrets. """
self.cipher_generate_keys()
assert self.cipher_keys
# Shamir polynomial for each access group
self.access_group_polynomial_coeffs()
assert self.d
# ID for each participant
self.random_id = common.provide_id(self.n, self.hash_len, self.p)
self.cipher_encrypt_all_secrets()
return self.compute_all_key_shares()
def main():
""" This example shows low-level functions for splitting
and combining secrets with multi-secret sharing
scheme by Roy & Adhikari. """
# large prime from NIST P-256 elliptic curve
p256 = 2**256 - 2**224 + 2**192 + 2**96 - 1
# multi secret sharing parameters
s_secrets = [7, 313, 671] # s_i
n_participants = 3
# access structure: to which secret what group has access
# Gamma(s_i) = [A1, A2, ... Al], Aq = (P1, P2, Pm), q=1,2...l
A1 = [1, 3]
# gamma1 is a group of users authorized to reconstruct s1
gamma1 = [A1]
gamma2 = [[1, 2], [2, 3]] # A1, A2 implicitly
gamma3 = [[1, 2,
3]] # to secret s3 only all 3 users together can gain access
access_structures = [gamma1, gamma2, gamma3]
# TODO: in GUI choosing access structures on a matrix
# Create a Dealer
dealer = multisecret.MultiSecretRoyAdhikari.Dealer(p256, n_participants,
s_secrets,
access_structures)
dealer.random_id = common.provide_id(
n_participants, dealer.hash_len,
dealer.p) # a list of IDs stored internally
dealer.master_shares_x = dealer.choose_distinct_master_shares_x()
dealer.access_group_polynomial_coeffs()
dealer.compute_all_pseudo_shares()
dealer.compute_all_public_shares_M()
print('obtained shares', dealer.pseudo_shares[0][0])
obtained_shares = []
for share in dealer.pseudo_shares[0][0]:
obtained_shares.append(int.from_bytes(share, byteorder='big'))
print('obtained shares', obtained_shares)
combined_secret = dealer.combine_secret(0, 0, obtained_shares)
print('Combined secret s1', combined_secret)