def _generate_triple_candidates(self, n):
"""Generates triple candidates for use in the BeDOZa protocol.
Returns a deferred that will eventually yield a list of 3n
shares of type viff.bedoza.shares.BeDOZaShare corresponding to
n multiplicative tuples. The first n are the a's, then comes n
b's followed by n c's.
The triples are only candidates because consistency of the
triples is only half-way guaranteed in the precense of active
adversaries. More concretely, the triples returned by this
method are guaranteed - even in the precense of an active
adversary - to be of the right size. But they may not satisfy
the equation
c = a * b.
"""
self.runtime.increment_pc()
gen = PartialShareGenerator(self.Zp, self.runtime, self.random,
self.paillier)
partial_shares = []
for _ in xrange(2 * n):
partial_shares.append(
gen.generate_share(self.random.randint(0,
self.Zp.modulus - 1)))
partial_shares_c = self._full_mul(partial_shares[0:n],
partial_shares[n:2 * n])
full_shares = add_macs(self.runtime, self.Zp, self.u_bound, self.alpha,
self.random, self.paillier,
partial_shares + partial_shares_c)
return full_shares
def _generate_triple_candidates(self, n):
"""Generates triple candidates for use in the BeDOZa protocol.
Returns a deferred that will eventually yield a list of 3n
shares of type viff.bedoza.shares.BeDOZaShare corresponding to
n multiplicative tuples. The first n are the a's, then comes n
b's followed by n c's.
The triples are only candidates because consistency of the
triples is only half-way guaranteed in the precense of active
adversaries. More concretely, the triples returned by this
method are guaranteed - even in the precense of an active
adversary - to be of the right size. But they may not satisfy
the equation
c = a * b.
"""
self.runtime.increment_pc()
gen = PartialShareGenerator(self.Zp, self.runtime, self.random,
self.paillier)
partial_shares = []
for _ in xrange(2 * n):
partial_shares.append(
gen.generate_share(
self.random.randint(0, self.Zp.modulus - 1)))
partial_shares_c = self._full_mul(partial_shares[0: n],
partial_shares[n: 2 * n])
full_shares = add_macs(self.runtime, self.Zp, self.u_bound, self.alpha,
self.random, self.paillier,
partial_shares + partial_shares_c)
return full_shares
def partial_share(random, runtime, Zp, val, paillier=None):
if not paillier:
paillier_random = Random(random.getrandbits(128))
paillier = ModifiedPaillier(runtime, paillier_random)
share_random = Random(random.getrandbits(128))
gen = PartialShareGenerator(Zp, runtime, share_random, paillier)
return gen.generate_share(Zp(val))
def partial_share(random, runtime, Zp, val, paillier=None):
if not paillier:
paillier_random = Random(random.getrandbits(128))
paillier = ModifiedPaillier(runtime, paillier_random)
share_random = Random(random.getrandbits(128))
gen = PartialShareGenerator(Zp, runtime, share_random, paillier)
return gen.generate_share(Zp(val))