import numpy as np from groth_poly_commit import Scalar, poly_commit, create_proof, verify_proof K = Scalar # Just use the same finite field we put in the polynomial commitment scheme file #p = 0x40000000000000000000000000000000224698fc094cf91b992d30ed00000001 #K = FiniteField(p) R. = LaurentPolynomialRing(K) var_one = K(1) var_x = K(4) var_y = K(6) var_s = K(1) var_xy = var_x * var_y var_sxy = var_s * var_xy var_1_neg_s = var_one - var_s var_x_y = var_x + var_y var_1_neg_s_x_y = var_1_neg_s * var_x_y var_s_neg_1 = -var_1_neg_s var_zero = K(0) public_v = var_s * (var_x * var_y) + (1 - var_s) * (var_x + var_y) a = np.array([ var_one, var_x, var_xy, var_1_neg_s, var_s ]) b = np.array([ var_one, var_y, var_s, var_x_y, var_s_neg_1 ]) c = np.array([ var_one, var_xy, var_sxy, var_1_neg_s_x_y, var_zero ]) assert len(a) == len(b) assert len(b) == len(c) for i, (a_i, b_i, c_i) in enumerate(zip(a, b, c), 1): try: assert a_i * b_i == c_i except AssertionError: print("Error for %i" % i) raise # 1 - s = -(s - 1) u1 = np.array([0, 0, 0, 1, 0]) v1 = np.array([0, 0, 0, 0, 1]) w1 = np.array([0, 0, 0, 0, 0]) k1 = 0 assert a.dot(u1) + b.dot(v1) + c.dot(w1) == k1 # xy = xy u2 = np.array([0, 0, 1, 0, 0]) v2 = np.array([0, 0, 0, 0, 0]) w2 = np.array([0, -1, 0, 0, 0]) k2 = 0 assert a.dot(u2) + b.dot(v2) + c.dot(w2) == k2 # s = s u3 = np.array([0, 0, 0, 0, -1]) v3 = np.array([0, 0, 1, 0, 0]) w3 = np.array([0, 0, 0, 0, 0]) k3 = 0 assert a.dot(u3) + b.dot(v3) + c.dot(w3) == k3 # zero = 0 u4 = np.array([0, 0, 0, 0, 0]) v4 = np.array([0, 0, 0, 0, 0]) w4 = np.array([0, 0, 0, 0, 1]) k4 = 0 assert a.dot(u4) + b.dot(v4) + c.dot(w4) == k4 # 1 - s u5 = np.array([1, 0, 0, -1, 0]) v5 = np.array([0, 0, -1, 0, 0]) w5 = np.array([0, 0, 0, 0, 0]) k5 = 0 assert a.dot(u5) + b.dot(v5) + c.dot(w5) == k5 # x + y u6 = np.array([0, 1, 0, 0, 0]) v6 = np.array([0, 1, 0, -1, 0]) w6 = np.array([0, 0, 0, 0, 0]) k6 = 0 assert a.dot(u6) + b.dot(v6) + c.dot(w6) == k6 # Final check: # v = s(xy) + (1 - s)(x + y) u7 = np.array([0, 0, 0, 0, 0]) v7 = np.array([0, 0, 0, 0, 0]) w7 = np.array([0, 0, 1, 1, 0]) k7 = public_v assert a.dot(u7) + b.dot(v7) + c.dot(w7) == k7 u = np.vstack((u1, u2, u3, u4, u5, u6, u7)) v = np.vstack((v1, v2, v3, v4, v5, v6, v7)) w = np.vstack((w1, w2, w3, w4, w5, w6, w7)) assert u.shape == v.shape assert u.shape == w.shape k = np.array((k1, k2, k3, k4, k5, k6, k7)) p = K(0) for i, (a_i, b_i, c_i) in enumerate(zip(a, b, c), 1): #print(a_i, "\t", b_i, "\t", c_i) p += y**i * (a_i * b_i - c_i) print(p) p = K(0) for q, (u_q, v_q, w_q, k_q) in enumerate(zip(u, v, w, k)): p += y**q * (a.dot(u_q) + b.dot(v_q) + c.dot(w_q) - k_q) print(p) n = len(a) assert len(b) == n assert len(c) == n assert u.shape == (7, n) assert v.shape == u.shape assert w.shape == u.shape assert k.shape == (7,) r_x_y = 0 s_x_y = 0 for i, (a_i, b_i, c_i) in enumerate(zip(a, b, c), 1): assert 1 <= i <= n r_x_y += x**i * y**i * a_i r_x_y += x**-i * y**-i * b_i r_x_y += x**(-i - n) * y**(-i - n) * c_i u_i = u.T[i - 1] v_i = v.T[i - 1] w_i = w.T[i - 1] u_i_Y = 0 v_i_Y = 0 w_i_Y = 0 for q, (u_q_i, v_q_i, w_q_i) in enumerate(zip(u_i, v_i, w_i), 1): assert 1 <= q <= 7 u_i_Y += y**q * u_q_i v_i_Y += y**q * v_q_i w_i_Y += y**q * w_q_i s_x_y += u_i_Y * x**-i + v_i_Y * x**i + w_i_Y * x**(i + n) k_y = 0 for q, k_q in enumerate(k, 1): assert 1 <= q <= 7 k_y += y**q * k_q # Section 6, Figure 2 # # zkP1 # 4 blinding factors since we evaluate r(X, Y) 3 times # Blind r(X, Y) for i in range(1, 4 + 1): blind_c_i = K.random_element() r_x_y += x**(-2*n - i) * y**(-2*n - i) * blind_c_i # Commit to r(X, Y) s_prime_x_y = y**n * s_x_y for i in range(1, n): s_prime_x_y -= (y**i + y**-i) * x**(i + n) r_x_1 = r_x_y(y=K(1)) t_x_y = r_x_1 * (r_x_y + s_prime_x_y) - y**n * k_y # This can be opened to r(X, Y) since r(X, Y) = r(XY, 1) r_x_1_scaled = (r_x_1 * x**(3*n - 1)).univariate_polynomial() rx1_commit_blind, rx1_commit = poly_commit(r_x_1_scaled) print("===================") print(" t(X, Y)") print("===================") power_dict = ["⁰", "¹", "²", "³", "⁴", "⁵", "⁶", "⁷", "⁸", "⁹"] def superscript(number): sign = "" if number < 0: sign = "⁻" number = -number return sign + "".join([power_dict[int(digit)] for digit in list(str(number))]) decorated = [] for (x_power, y_power), coeff in t_x_y.dict().items(): if coeff == 1: coeff = "" display = "%s X%s Y%s" % (coeff, superscript(x_power), superscript(y_power)) decorated.append([x_power, y_power, display]) decorated.sort(key=lambda x: (x[0], -x[1])) for _, _, display in decorated: print(display) print() print("Constant coefficient:", t_x_y.constant_coefficient()) print() # zkV1 # Send a random y challenge_y = K.random_element() # zkP2 # Commit to t(X, y) t_x = t_x_y(y=challenge_y) t_x = t_x.univariate_polynomial() print("===================") print(" t(X, y)") print("===================") print(t_x.dict()) print() print("Constant coefficient:", t_x.constant_coefficient()) # Split the polynomial into low and hi versions t_lo_x = 0 t_hi_x = 0 smallest_power = -min(t_x.dict().keys()) for power, coeff in t_x.dict().items(): assert power != 0 if power < 0: t_lo_x += x**(smallest_power + power) * coeff else: t_hi_x += x**(power - 1) * coeff d = t_lo_x.degree() + 1 t_lo_x = t_lo_x.univariate_polynomial() t_hi_x = t_hi_x.univariate_polynomial() assert (t_lo_x * x**-d + t_hi_x * x).univariate_polynomial() == t_x T_lo_commit_blind, T_lo = poly_commit(t_lo_x) T_hi_commit_blind, T_hi = poly_commit(t_hi_x) # zkV2 # Send a random z challenge_z = K.random_element() # zkP3 # Evaluate a = r(z, 1) a = r_x_y(x=challenge_z, y=K(1)) # Evaluate b = r(z, y) b = r_x_y(x=challenge_z, y=challenge_y) # Evaluate t = t(z, y) t = t_x_y(x=challenge_z, y=challenge_y) # Evaluate s = s(z, y) s = s_prime_x_y(x=challenge_z, y=challenge_y) # Calculate equivalent openings # s'(X, Y) is known by both prover and verifier a_proof = create_proof(r_x_1_scaled, rx1_commit_blind, challenge_z) assert a_proof.poly_commit == rx1_commit b_proof = create_proof(r_x_1_scaled, rx1_commit_blind, challenge_y * challenge_z) assert b_proof.poly_commit == rx1_commit t_proof_lo = create_proof(t_lo_x, T_lo_commit_blind, challenge_z) assert t_proof_lo.poly_commit == T_lo t_proof_hi = create_proof(t_hi_x, T_hi_commit_blind, challenge_z) assert t_proof_hi.poly_commit == T_hi # Signature of correct computation not yet implemented # So just use s for now as is # Scaling factor verifier_rescale = challenge_z**(-3*n + 1) assert a_proof.value * verifier_rescale == a verifier_rescale = (challenge_y * challenge_z)**(-3*n + 1) assert b_proof.value * verifier_rescale == b # zkV3 # Recalculate t from a, b and s t_new = t_proof_lo.value * challenge_z**-d + t_proof_hi.value * challenge_z assert t_new == t t = t_new k = (y**n * k_y)(y=challenge_y) t_new = a * (b + s) - k assert t_new == t # Verify polynomial commitments