Files
darkfi/script/research/halo/groth_poly_commit.py
2021-09-16 12:07:51 +02:00

178 lines
5.9 KiB
Python

# This file was *autogenerated* from the file groth_poly_commit.sage
from sage.all_cmdline import * # import sage library
_sage_const_0x40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001 = Integer(0x40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001); _sage_const_0x00 = Integer(0x00); _sage_const_0x05 = Integer(0x05); _sage_const_0x40000000000000000000000000000000224698fc0994a8dd8c46eb2100000000 = Integer(0x40000000000000000000000000000000224698fc0994a8dd8c46eb2100000000); _sage_const_0x02 = Integer(0x02); _sage_const_0x40000000000000000000000000000000224698fc094cf91b992d30ed00000001 = Integer(0x40000000000000000000000000000000224698fc094cf91b992d30ed00000001); _sage_const_1000 = Integer(1000); _sage_const_1 = Integer(1); _sage_const_110 = Integer(110); _sage_const_2 = Integer(2); _sage_const_56 = Integer(56); _sage_const_89 = Integer(89); _sage_const_6543 = Integer(6543); _sage_const_0 = Integer(0); _sage_const_77 = Integer(77)
import numpy as np
from collections import namedtuple
PolyProof = namedtuple("PolyProof", [
"poly_commit",
"poly_blind_commit",
"poly_response",
"poly_blind_respond",
"x_blind_factors",
"evaluation_commits",
"evaluation_response",
"value"
])
# Implementation of Groth09 inner product proof
q = _sage_const_0x40000000000000000000000000000000224698fc0994a8dd8c46eb2100000001
K = GF(q)
a = K(_sage_const_0x00 )
b = K(_sage_const_0x05 )
E = EllipticCurve(K, (a, b))
G = E(_sage_const_0x40000000000000000000000000000000224698fc0994a8dd8c46eb2100000000 , _sage_const_0x02 )
p = _sage_const_0x40000000000000000000000000000000224698fc094cf91b992d30ed00000001
assert E.order() == p
Scalar = GF(p)
# Create some generator points. Normally we would use hash to curve.
# All these points will be generators since the curve is a cyclic group
H = E.random_element()
G_vec = [E.random_element() for _ in range(_sage_const_1000 )]
def dot_product(x, y):
result = None
for x_i, y_i in zip(x, y):
if result is None:
result = int(x_i) * y_i
else:
result += int(x_i) * y_i
return result
def poly_commit(p):
# Sage randomly orders terms. No guarantee about ordering.
#a = np.array(p.coefficients())
a = np.array([p[i] for i in range(p.degree() + _sage_const_1 )])
r = Scalar.random_element()
C_x = int(r) * H + dot_product(a, G_vec)
return (r, C_x)
def create_proof(p, r, x):
a = np.array([p[i] for i in range(p.degree() + _sage_const_1 )])
#a = np.array(p.coefficients())
x = np.array([x**i for i in range(p.degree() + _sage_const_1 )])
# Evaluate the polynomial
z = a.dot(x)
assert len(a) == len(x)
# We will now construct a proof
# Commitments
t = Scalar.random_element()
#r = Scalar.random_element()
s = Scalar.random_element()
C_z = int(t) * H + int(z) * G
C_x = int(r) * H + dot_product(a, G_vec)
C_y = int(s) * H + dot_product(x, G_vec)
d_x = np.array([Scalar.random_element() for _ in range(len(x))])
d_y = np.array([Scalar.random_element() for _ in range(len(x))])
r_d = Scalar.random_element()
s_d = Scalar.random_element()
A_d = int(r_d) * H + dot_product(d_x, G_vec)
B_d = int(s_d) * H + dot_product(d_y, G_vec)
# (cx + d_x)(cy + d_y) = d_x d_y + c(x d_y + y d_x) + c^2 xy
t_0 = Scalar.random_element()
t_1 = Scalar.random_element()
C_0 = int(t_0) * H + int(d_x.dot(d_y)) * G
C_1 = int(t_1) * H + int(a.dot(d_y) + x.dot(d_x)) * G
# Challenge
# Using the Fiat-Shamir transform, we would hash the transcript
#c = Scalar.random_element()
c = _sage_const_110
# Responses
f_x = c * a + d_x
f_y = c * x + d_y
r_x = c * r + r_d
s_y = c * s + s_d
t_z = c**_sage_const_2 * t + c * t_1 + t_0
# Verify
#B_d = int(s_d) * H + dot_product(d_y, G_vec)
#C_y = int(s) * H + dot_product(x, G_vec)
assert int(c) * C_x + A_d == int(r_x) * H + dot_product(f_x, G_vec)
assert int(c) * C_y + B_d == int(s_y) * H + dot_product(f_y, G_vec)
# Actual inner product check
# Comm(f_x f_y) == e^2 C_z + c Comm(x d_y + y d_x) + Comm(d_x d_y)
assert int(t_z) * H + int(f_x.dot(f_y)) * G == int(c**_sage_const_2 ) * C_z + int(c) * C_1 + C_0
return PolyProof(
poly_commit=C_x,
poly_blind_commit=A_d,
poly_response=f_x,
poly_blind_respond=r_x,
x_blind_factors=(s_d, d_y, s),
evaluation_commits=(C_0, C_1, C_z),
evaluation_response=t_z,
value=z
)
def verify_proof(proof, x):
C_x = proof.poly_commit
A_d = proof.poly_blind_commit
f_x = proof.poly_response
r_x = proof.poly_blind_respond
(s_d, d_y, s) = proof.x_blind_factors
(C_0, C_1, C_z) = proof.evaluation_commits
t_z = proof.evaluation_response
z = proof.value
x = np.array([x**i for i in range(len(a))])
c = _sage_const_110
f_y = c * x + d_y
s_y = c * s + s_d
B_d = int(s_d) * H + dot_product(d_y, G_vec)
C_y = int(s) * H + dot_product(x, G_vec)
if int(c) * C_x + A_d != int(r_x) * H + dot_product(f_x, G_vec):
return False
if int(c) * C_y + B_d != int(s_y) * H + dot_product(f_y, G_vec):
return False
# Actual inner product check
# Comm(f_x f_y) == e^2 C_z + c Comm(x d_y + y d_x) + Comm(d_x d_y)
if int(t_z) * H + int(f_x.dot(f_y)) * G != int(c**_sage_const_2 ) * C_z + int(c) * C_1 + C_0:
return False
return True
#R = LaurentPolynomialRing(Scalar, names=('x',)); (x,) = R._first_ngens(1)
#a = np.array([
# Scalar(_sage_const_110 ), Scalar(_sage_const_56 ), Scalar(_sage_const_89 ), Scalar(_sage_const_6543 ), Scalar(_sage_const_2 )
#])
#p = _sage_const_0
#for i, a_i in enumerate(a):
# p += a_i * x**i
#print(p)
#xx = Scalar(_sage_const_77 )
#r, commit = poly_commit(p)
#proof = create_proof(p, r, xx)
#assert verify_proof(proof, xx)
#assert proof.poly_commit == commit
#assert proof.value == p(xx)