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darkfi/script/research/bulletproof-mpc/proof_mpc.sage
2023-09-21 16:19:15 +03:00

271 lines
14 KiB
Python

'''
bulletproof protocol 2 with multi-exponentiation.
'''
load('../mpc/curve.sage')
load('../mpc/ec_share.sage')
load('../mpc/share.sage')
load('../mpc/beaver.sage')
load('utils.sage')
class MpcProof(object):
def __init__(self, transcript, Q, G_factors, H_factors, G, H, a_shares, b_shares, source, party_id):
'''
create inner product proof
'''
self.n = len(G)
self.m = self.n
assert (self.n == len(H) == len(H_factors) == len(a_shares) == len(b_shares))
self.source = source
self.party_id=party_id
self.Q = Q
self.G = G
self.H = H
self.G_factors = G_factors
self.H_factors = H_factors
self.transcript = transcript
self.L = []
self.R = []
L_l = []
R_l = []
self.c_l = []
self.c_r = []
self.a_shares_l = []
self.a_shares_r = []
self.b_shares_l = []
self.b_shares_r = []
self.G_hist = []
self.H_hist = []
if self.n!=1:
self.n /=2
a_shares_l, a_shares_r = a_shares[0:self.n], a_shares[self.n:]
b_shares_l, b_shares_r = b_shares[0:self.n], b_shares[self.n:]
self.a_shares_l += [a_shares_l.copy()]
self.a_shares_r += [a_shares_r.copy()]
self.b_shares_l += [b_shares_l.copy()]
self.b_shares_r += [b_shares_r.copy()]
G_l, G_r = G[0:self.n], G[self.n:]
H_l, H_r = H[0:self.n], H[self.n:]
self.G_hist+=[[G_l, G_r]]
self.H_hist+=[[H_l, H_r]]
# authenticated inner product
#TODO multiplication
c_shares_l = [MultiplicationAuthenticatedShares(a_share, b_share, self.source.triplet(self.party_id), self.party_id) for a_share, b_share in zip(a_shares_l, b_shares_r)]
c_shares_r = [MultiplicationAuthenticatedShares(a_share, b_share, self.source.triplet(self.party_id), self.party_id) for a_share, b_share in zip(a_shares_r, b_shares_l)]
self.c_l += [c_shares_l]
self.c_r += [c_shares_r]
u = K(1)
u_inv = 1/u
for i in range(self.n):
# a_prime
a_shares_l[i] = a_shares_l[i].mul_scalar(u) + a_shares_r[i].mul_scalar(u_inv)
# p_prime
b_shares_l[i] = b_shares_l[i].mul_scalar(u_inv) + b_shares_r[i].mul_scalar(u)
#TODO (research) get pt from share.
# G_prime
G_l[i] = to_ec_shares(CurvePoint.msm([G_l[i].share, G_r[i].share], [u_inv * G_factors[i], u * G_factors[self.n+i]]))
# H_prime
H_l[i] = to_ec_shares(CurvePoint.msm([H_l[i].share, H_r[i].share], [u * H_factors[i], u_inv * H_factors[self.n+i]]))
a_shares = a_shares_l # a is a_prime
b_shares = b_shares_l # b is b_prime
G = G_l # G is G_prime
H = H_l # H is H_prime
while self.n!=1:
self.n /=2
a_shares_l, a_shares_r = a_shares[0:self.n], a_shares[self.n:] # a_prime_l, a_prime_r
b_shares_l, b_shares_r = b_shares[0:self.n], b_shares[self.n:] # b_prime_l, b_prime_r
self.a_shares_l += [a_shares_l.copy()]
self.a_shares_r += [a_shares_r.copy()]
self.b_shares_l += [b_shares_l.copy()]
self.b_shares_r += [b_shares_r.copy()]
G_l, G_r = G[0:self.n], G[self.n:] # G_prime_l, G_prime_r
H_l, H_r = H[0:self.n], H[self.n:] # H_prime_l, H_prime_r
self.G_hist+=[[G_l, G_r]]
self.H_hist+=[[H_l, H_r]]
c_shares_l = [MultiplicationAuthenticatedShares(a_share, b_share, self.source.triplet(self.party_id), self.party_id) for (a_share,b_share) in zip(a_shares_l, b_shares_r)] # c_prime_l
c_shares_r = [MultiplicationAuthenticatedShares(a_share, b_share, self.source.triplet(self.party_id), self.party_id) for (a_share,b_share) in zip(a_shares_r, b_shares_l)] # c_prime_r
self.c_l += [c_shares_l]
self.c_r += [c_shares_r]
u = K(1)
u_inv = 1/u
for i in range(self.n):
# u * a_prime_l + u^{-1} * a_prime_r
a_shares_l[i] = a_shares_l[i].mul_scalar(u) + a_shares_r[i].mul_scalar(u_inv)
# u^{-1} * b_prime_l + u * b_prime_r
b_shares_l[i] = b_shares_l[i].mul_scalar(u_inv) + b_shares_r[i].mul_scalar(u)
# G_l_prime
G_l[i] = to_ec_shares(CurvePoint.msm([G_l[i].share, G_r[i].share], [u_inv, u]))
# H_l_prime
H_l[i] = to_ec_shares(CurvePoint.msm([H_l[i].share, H_r[i].share], [u, u_inv]))
a_shares = a_shares_l
b_shares = b_shares_l
G = G_l
H = H_l
self.a_shares = a_shares[0]
self.b_shares = b_shares[0]
self.G = G
self.H = H
def create(self, their_c_l_shares, their_c_r_shares):
'''
create inner product proof
'''
self.c_l = [[my_c_l[i].mul(their_c_l[i].d, their_c_l[i].e) for i in range(len(my_c_l))] for my_c_l, their_c_l in zip(self.c_l, their_c_l_shares)]
self.c_r = [[my_c_r[i].mul(their_c_r[i].d, their_c_r[i].e) for i in range(len(my_c_r))] for my_c_r, their_c_r in zip(self.c_r, their_c_r_shares)]
print('c_l: {}'.format(self.c_l))
print('c_r: {}'.format(self.c_r))
print('c: {}'.format(sum([c_l[i].authenticated_open(c_r[i]) for i in range(len(self.c_l[0])) for c_l, c_r in zip(self.c_l, self.c_r)])))
# create L,R for proof validation
L_l = []
R_l = []
counter = 0
if self.m!=1:
self.m /= 2
al_share_g = [al_share.mul_scalar(g) for al_share, g in zip(self.a_shares_l[counter], self.G_factors[self.m:2*self.m])]
br_share_h = [br_share.mul_scalar(h) for br_share, h in zip(self.b_shares_r[counter], self.H_factors[0:self.m])]
L_gr_al_g_share = MSM(self.G_hist[counter][1], al_share_g, self.source, self.party_id)
L_hl_br_h_share = MSM(self.H_hist[counter][0], br_share_h, self.source, self.party_id)
L_q_cl_share = MSM(self.Q, self.c_l[counter], self.source, self.party_id)
# L, R
# note that P = L*R
L_shares = [L_gr_al_g_share, L_hl_br_h_share , L_q_cl_share]
ar_share_g = [ar_share.mul_scalar(g) for ar_share, g in zip(self.a_shares_r[counter], G_factors[0:self.m])]
bl_share_g = [bl_share.mul_scalar(h) for bl_share, h in zip(self.b_shares_l[counter], H_factors[self.m:2*self.m])]
R_gl_ar_g_share = MSM(self.G_hist[counter][0], ar_share_g, self.source, self.party_id)
R_hr_bl_h_share = MSM(self.H_hist[counter][1], bl_share_g, self.source, self.party_id)
R_q_cr_share = MSM(Q, self.c_r[counter], self.source, self.party_id)
R_shares = [R_gl_ar_g_share, R_hr_bl_h_share, R_q_cr_share]
L_l += [L_shares]
R_l += [R_shares]
counter +=1
while self.m!=1:
self.m /=2
# L_prime
L_gr_al_share = MSM(self.G_hist[counter][1], self.a_shares_l[counter], self.source, self.party_id)
L_hl_br_share = MSM(self.H_hist[counter][0], self.b_shares_r[counter], self.source, self.party_id)
L_q_cl_share = MSM(self.Q, self.c_l[counter], self.source, self.party_id)
L_shares = [L_gr_al_share, L_hl_br_share, L_q_cl_share]
# R_prime
R_gl_ar_share = MSM(self.G_hist[counter][0], a_shares_r, self.source, self.party_id)
R_hr_bl_share = MSM(self.H_hist[counter][1], b_shares_l, self.source, self.party_id)
R_q_cr_share = MSM(Q, self.c_r[counter], self.source, self.party_id)
R_shares = [R_gl_ar_share, R_hr_bl_share, R_q_cr_share]
L_l += [L_shares]
R_l += [R_shares]
counter +=1
#
self.lhs = L_l
self.rhs = R_l
def challenges(self, n, verifier):
challenges = []
challenges_inv = []
lg_n = len(self.lhs)
for L, R in zip(self.lhs, self.rhs):
#verifier.append_message(b'L', bytes(''.join([l.__str__() for l in [L]]), encoding='utf-8'))
#verifier.append_message(b'R', bytes(''.join([r.__str__() for r in [R]]), encoding='utf-8'))
#u = K(verifier.challenge_bytes(b'u'))
u = K(1)
u_inv = 1/u
challenges += [u]
challenges_inv += [u_inv]
inv_prod = K(1)
for u_inv in challenges_inv:
inv_prod *=K(1)
challenges_sq = [i*i for i in challenges]
challenges_inv_sq = [i*i for i in challenges_inv]
mul_inv = K(1)
for i in challenges_inv:
mul_inv *=i
S = [mul_inv]
for i in range(1,n):
lg_i = 32 - 1 - countZeros(i)
k = 1 << lg_i
u_lg_i_sq = challenges_sq[(lg_n -1) - lg_i]
S += [S[i-k] * u_lg_i_sq]
return challenges_sq, challenges_inv_sq, S
def calculate_c_shares(self, n, verifier, G_factors, H_factors):
self.u_sq, self.u_inv_sq, self.s = self.challenges(n, verifier)
self.gas_shares = [self.a_shares.mul_scalar(s_i * g_i) for g_i, s_i in zip(G_factors, self.s)][:n]
# inverse of count is reverse
self.inv_s = reversed(self.s)
self.hbs_shares = [self.b_shares.mul_scalar(s_i_inv * h_i) for h_i, s_i_inv in zip(H_factors, self.inv_s)]
#TODO (fix) this should be shares, this is fake shares!
self.neg_u_sq = [i*K(-1) for i in self.u_sq]
self.neg_u_inv_sq = [i*K(-1) for i in self.u_inv_sq]
# P
## u^c
self.my_c_shares = [MultiplicationAuthenticatedShares(a_share, b_share, self.source.triplet(self.party_id), self.party_id) for a_share, b_share in zip([self.a_shares], [self.b_shares])]
def open_lr(self, Q, G, H, their_c_shares_de, peer_lhs, peer_rhs):
c_shares = [my_c_share.mul(their_c_shares_de[i][0], their_c_shares_de[i][1]) for i, my_c_share in enumerate(self.my_c_shares)]
self.res_p_1 = MSM(Q, c_shares, self.source, self.party_id)
## g^{g_factor_a_s}
self.res_p_2 = MSM(G, self.gas_shares, self.source, self.party_id)
## h^{h_factor_b_s}
self.res_p_3 = MSM(H, self.hbs_shares, self.source, self.party_id)
## L
for my_lhs, their_lhs in zip(self.lhs, peer_lhs):
L_triad = []
for my_lhs_i, their_lhs_i in zip(my_lhs, their_lhs):
my_lhs_i_de = [[ps.d, ps.e] for ps in my_lhs_i.point_scalars]
#print("lhs point scalars: {}".format(their_lhs_i.point_scalars))
their_lhs_i_de = [[ps.d, ps.e] for ps in their_lhs_i.point_scalars]
#my_lhs_i_share = my_lhs_i.msm(their_lhs_i_de)
#their_rhs_i_share = their_lhs_i.msm(my_lhs_i_de)
#L_triad += [ECAuthenticatedShare(my_lhs_i_share.authenticated_open(their_rhs_i_share))]
#L_triad += [lhs_i]
lhs_i_share = my_lhs_i.msm(their_lhs_i_de)
#L_triad += [ECAuthenticatedShare(my_lhs_i_share.authenticated_open(their_rhs_i_share))]
L_triad += [lhs_i_share]
#L += [sum_shares(L_triad, self.source, self.party_id)]
self.L += [sum_shares(L_triad, self.source, self.party_id)]
## R
for my_rhs, their_rhs in zip(self.rhs, peer_rhs):
R_triad = []
for my_rhs_i, their_rhs_i in zip(my_rhs, their_rhs):
my_rhs_i_de = [[ps.d, ps.e] for ps in my_rhs_i.point_scalars]
their_rhs_i_de = [[ps.d, ps.e] for ps in their_rhs_i.point_scalars]
#my_rhs_i_share = my_rhs_i.msm(their_rhs_i_de)
#their_rhs_i_share = their_rhs_i.msm(my_rhs_i_de)
#R_triad += [ECAuthenticatedShare(my_lhs_i_share.authenticated_open(their_rhs_i_share))]
rhs_i_share = my_rhs_i.msm(their_rhs_i_de)
R_triad += [rhs_i_share]
#R_triad += [rhs_i]
#R += [sum_shares(R_triad, self.source, self.party_id)]
self.R += [sum_shares(R_triad, self.source, self.party_id)]
# L^(u^2)
#temp = K(random.randint(0,p))
temp = K(0)
self.res_p_4 = MSM(self.L, [AuthenticatedShare(temp, self.source, self.party_id) if self.party_id==0 else AuthenticatedShare(neg_u_sq_i-temp, self.source, self.party_id) for neg_u_sq_i in self.neg_u_sq], self.source, self.party_id)
# R^(u^-2)
self.res_p_5 = MSM(self.R, [AuthenticatedShare(temp, self.source, self.party_id) if self.party_id==0 else AuthenticatedShare(neg_u_inv_sq_i-temp, self.source, self.party_id) for neg_u_inv_sq_i in self.neg_u_inv_sq], self.source, self.party_id)
# P prime = L^{u^2} * P * R^{u^{-1}}
self.res_p = [self.res_p_1, self.res_p_2, self.res_p_3, self.res_p_4, self.res_p_5]
def open_and_validate_P(self, res_p, P):
P_msm_parts = []
for my_res_p, their_res_p in zip(self.res_p, res_p):
my_res_de = [[ps.d, ps.e] for ps in my_res_p.point_scalars]
their_res_de = [[ps.d, ps.e] for ps in their_res_p.point_scalars]
lhs = my_res_p.msm(their_res_de)
rhs = their_res_p.msm(my_res_de)
p_part = lhs.authenticated_open(rhs)
print('p_part: {}'.format(p_part))
P_msm_parts += [p_part]
# P prime == H(u^{-1} * a_prime_r, u * a_prime_l, u * b_prime_r, u ^ {-1} * b_prime_l, c_prime)
my_P = sum(P_msm_parts)
assert (my_P == P), 'P: {}, expected: {}'.format(my_P, P)