Files
darkfi/script/research/mpc/share.sage

96 lines
3.6 KiB
Python

import random
load('../mpc/curve.sage')
load('../mpc/ec_share.sage')
def open_2pc(party0_share, party1_share):
return party0_share + party1_share
def verify_2pc_mac_check(party0_mac, party1_mac):
assert party0_mac+party1_mac == 0
global_key = random.randint(0, p)
class AuthenticatedShare(object):
"""
additive share
"""
def __init__(self, share, source, party_id, mac=None, modifier=None):
self.share = share
self.mac = global_key * self.share if mac==None else mac
self.public_modifier = 0 if modifier == None else modifier # carry out extra addition/subtraction by public scalars until opening
self.party_id = party_id
self.source = source
def copy(self):
return AuthenticatedShare(K(self.share), self.source, self.party_id, K(self.mac), K(self.public_modifier))
def __repr__(self):
return "share: %s, mac: %s"%(self.share, self.mac)
# SPDZ mac authentication
def authenticated_open(self, peer_authenticated_share):
opened_share = open_2pc(self.share, peer_authenticated_share.share)
mac_key = random.randint(0,global_key)
mac_share = mac_key * (opened_share + self.public_modifier) - self.mac
peer_mac_key = global_key - mac_key
peer_mac_share = peer_mac_key * (opened_share + peer_authenticated_share.public_modifier) - peer_authenticated_share.mac
#assert (mac_share + peer_mac_share) == 0
return opened_share
def sub_scalar(self, scalar, party_id):
return AuthenticatedShare(self.share - scalar, self.mac, self.public_modifier + scalar) if party_id == 0 else AuthenticatedShare(self.share , self.mac, self.public_modifier + scalar)
def add_scalar(self, scalar, party_id):
return AuthenticatedShare(self.share + scalar, self.mac , self.public_modifier - scalar) if party_id ==0 else AuthenticatedShare(self.share, self.mac, self.public_modifier - scalar)
def mul_scalar(self, scalar):
return AuthenticatedShare(self.share * scalar, self.mac * scalar, self.public_modifier * scalar)
def mul_point(self, point):
return ECAuthenticatedShare(self.share * point, self.mac * point, self.public_modifier * point)
def __add__(self, rhs):
'''
add additive shares
'''
return AuthenticatedShare(self.share + rhs.share, self.mac + rhs.mac, self.public_modifier + rhs.public_modifier)
def __sub__(self, rhs):
'''
sub additive shares
'''
return AuthenticatedShare(self.share - rhs.share, self.mac - rhs.mac, self.public_modifier - rhs.public_modifier)
class MultiplicationAuthenticatedShares(object):
def __init__(self, alpha, beta, triplet, party_id):
# authenticated shares
self.alpha_as = alpha
self.beta_as = beta
self.a_as = triplet[0]
self.b_as = triplet[1]
self.c_as = triplet[2]
self.party_id = party_id
d1 = self.alpha_as - self.a_as
e1 = self.beta_as - self.b_as
self.d = d1
self.e = e1
def mul(self, d2, e2):
d = open_2pc(self.d.share, d2.share)
e = open_2pc(self.e.share, e2.share)
if self.party_id==0:
bd = self.b_as.mul_scalar(d)
ae = self.a_as.mul_scalar(e)
return (bd + ae + self.c_as).add_scalar(d*e, self.party_id)
else:
bd = self.b_as.mul_scalar(d)
ae = self.a_as.mul_scalar(e)
#return (bd + ae + self.c_as).add_scalar(d*e, self.party_id)
return bd + ae + self.c_as