// Copyright (c) 2022 Zano Project // Copyright (c) 2022 sowle (val@zano.org, crypto.sowle@gmail.com) // Distributed under the MIT/X11 software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. // // Note: This file originates from tests/functional_tests/crypto_tests.cpp #include "epee/include/misc_log_ex.h" #include "zarcanum.h" #include "crypto/range_proofs.h" #include "../currency_core/crypto_config.h" // TODO: move it to the crypto namespace crypto { const scalar_t c_zarcanum_z_coeff_s = { 0, 1, 0, 0 }; // c_scalar_2p64 const mp::uint256_t c_zarcanum_z_coeff_mp = c_zarcanum_z_coeff_s.as_boost_mp_type(); mp::uint256_t zarcanum_precalculate_l_div_z_D(const mp::uint128_t& pos_difficulty) { //LOG_PRINT_GREEN_L0(ENDL << "floor( l / (z * D) ) = " << c_scalar_L.as_boost_mp_type() / (c_zarcanum_z_coeff_mp * pos_difficulty)); return c_scalar_L.as_boost_mp_type() / (c_zarcanum_z_coeff_mp * pos_difficulty); // == floor( l / (z * D) ) } mp::uint256_t zarcanum_precalculate_z_l_div_z_D(const mp::uint128_t& pos_difficulty) { //LOG_PRINT_GREEN_L0(ENDL << "z * floor( l / (z * D) ) = " << c_zarcanum_z_coeff_mp * (c_scalar_L.as_boost_mp_type() / (c_zarcanum_z_coeff_mp * pos_difficulty))); return c_zarcanum_z_coeff_mp * (c_scalar_L.as_boost_mp_type() / (c_zarcanum_z_coeff_mp * pos_difficulty)); // == z * floor( l / (z * D) ) } bool zarcanum_check_main_pos_inequality(const hash& kernel_hash, const scalar_t& blinding_mask, const scalar_t& secret_q, const scalar_t& last_pow_block_id_hashed, const mp::uint256_t& z_l_div_z_D, uint64_t stake_amount, mp::uint256_t& lhs, mp::uint512_t& rhs) { scalar_t lhs_s = scalar_t(kernel_hash) * (blinding_mask + secret_q + last_pow_block_id_hashed); // == h * (f + q + f') mod l lhs = lhs_s.as_boost_mp_type(); rhs = static_cast(z_l_div_z_D) * stake_amount; // == floor( l / (z * D) ) * z * a //LOG_PRINT_GREEN_L0(ENDL << // "z_l_div_z_D = " << z_l_div_z_D << ENDL << // "stake_amount = " << stake_amount << ENDL << // "lhs = " << lhs << ENDL << // "rhs = " << rhs); return lhs < rhs; // h * (f + q + f') mod l < floor( l / (z * D) ) * z * a } #define CHECK_AND_FAIL_WITH_ERROR_IF_FALSE(cond, err_code) \ if (!(cond)) { LOG_PRINT_RED("zarcanum_generate_proof: \"" << #cond << "\" is false at " << LOCATION_SS << ENDL << "error code = " << err_code, LOG_LEVEL_3); \ if (p_err) { *p_err = err_code; } return false; } bool zarcanum_generate_proof(const hash& m, const hash& kernel_hash, const std::vector& ring, const point_t& pseudo_out_amount_commitment, const scalar_t& last_pow_block_id_hashed, const scalar_t& blinding_mask, const scalar_t& secret_q, uint64_t stake_amount, uint64_t secret_index, zarcanum_proof& result, uint8_t* p_err /* = nullptr */) { const scalar_t a = stake_amount; const scalar_t h = scalar_t(kernel_hash); const scalar_t f_plus_q = blinding_mask + secret_q; const scalar_t f_plus_q_plus_fp = f_plus_q + last_pow_block_id_hashed; const scalar_t lhs = h * f_plus_q_plus_fp; // == h * (f + q + f') mod l const mp::uint256_t d_mp = lhs.as_boost_mp_type() / (c_zarcanum_z_coeff_mp * stake_amount) + 1; result.d = scalar_t(d_mp); const scalar_t dz = result.d * c_zarcanum_z_coeff_s; const scalar_t ba = dz * a - lhs; // b_a = dza - h(f + q + f') const scalar_t bf = dz * f_plus_q - h * a; // b_f = dz(f + q) - ha const scalar_t x0 = scalar_t::random(), x1 = scalar_t::random(), x2 = scalar_t::random(); const scalar_t bx = x2 - h * x1 + dz * x0; // b_x = x'' - hx' + dzx point_t C = x0 * c_point_X + a * c_point_H + f_plus_q * c_point_G; point_t C_prime = x1 * c_point_X + f_plus_q * c_point_H + a * c_point_G; point_t E = bx * c_point_X + ba * c_point_H + bf * c_point_G; result.C = (c_scalar_1div8 * C).to_public_key(); result.C_prime = (c_scalar_1div8 * C_prime).to_public_key(); result.E = (c_scalar_1div8 * E).to_public_key(); // three proofs with a shared Fiat-Shamir challenge c // 1) linear composition proof for the fact, that C + C' = lin(X, H + G) = (x + x') X + (a + f + q) (H + G) // 2) linear composition proof for the fact, that C - C' = lin(X, H - G) = (x - x') X + (a - f - q) (H - G) // 3) Schnorr proof for the fact, that hC' - dzC + E + f'hH = lin(X) = x'' X point_t F = h * C_prime - dz * C + E + last_pow_block_id_hashed * h * c_point_H; scalar_t r0 = scalar_t::random(); scalar_t r1 = scalar_t::random(); scalar_t r2 = scalar_t::random(); scalar_t r3 = scalar_t::random(); scalar_t r4 = scalar_t::random(); point_t R_01 = r0 * c_point_X + r1 * c_point_H_plus_G; point_t R_23 = r2 * c_point_X + r3 * c_point_H_minus_G; point_t R_4 = r4 * c_point_G; hash_helper_t::hs_t hash_calc(3); hash_calc.add_32_chars(CRYPTO_HDS_ZARCANUM_PROOF_HASH); hash_calc.add_point(R_01); hash_calc.add_point(R_23); hash_calc.add_point(R_4); hash_calc.add_point(C + C_prime); hash_calc.add_point(C - C_prime); hash_calc.add_point(F); result.c = hash_calc.calc_hash(); result.y0 = r0 + result.c * (x0 + x1); // y_0 = r_0 + c (x + x') result.y1 = r1 + result.c * (a + f_plus_q); // y_1 = r_1 + c (a + f + q) result.y2 = r2 + result.c * (x0 - x1); // y_2 = r_2 + c (x - x') result.y3 = r3 + result.c * (a - f_plus_q); // y_3 = r_3 + c (a - f - q) result.y4 = r4 + result.c * x2; // y_4 = r_4 + c x'' // range proof for E const scalar_vec_t values = { ba }; // H component const scalar_vec_t masks = { bf }; // G component const scalar_vec_t masks2 = { bx }; // X component const std::vector E_1div8_vec_ptr = { &result.E }; if (!bppe_gen>(values, masks, masks2, E_1div8_vec_ptr, result.E_range_proof, p_err)) { return false; } // = four-layers ring signature data outline = // (j in [0, ring_size-1]) // layer 0 ring // se.outputs[j].stealth_address; // layer 0 secret (with respect to G) // in_contexts[i].in_ephemeral.sec; // layer 0 linkability // in.k_image; // // layer 1 ring // crypto::point_t(se.outputs[j].amount_commitment) - pseudo_out_amount_commitment; // layer 1 secret (with respect to G) // se.real_out_amount_blinding_mask - blinding_mask; // // additional layers for Zarcanum: // // layer 2 ring // C - A[j] - Q[j] // layer 2 secret (with respect to X) // x0 // // layer 3 ring // Q[j] // layer 3 secret (with respect to G) // secret_q return true; } bool zarcanum_verify_proof(const hash& kernel_hash, const public_key& commitment_1div8, const scalar_t& last_pow_block_id_hashed, const zarcanum_proof& proof, uint8_t* p_err /* = nullptr */) { return false; } } // namespace crypto