Return to ntt_fft_params.h CVS log | Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / strongswan / src / libstrongswan / math / libnttfft |
1.1 misho 1: /* 2: * Copyright (C) 2014-2016 Andreas Steffen 3: * HSR Hochschule fuer Technik Rapperswil 4: * 5: * This program is free software; you can redistribute it and/or modify it 6: * under the terms of the GNU General Public License as published by the 7: * Free Software Foundation; either version 2 of the License, or (at your 8: * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. 9: * 10: * This program is distributed in the hope that it will be useful, but 11: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 12: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13: * for more details. 14: */ 15: 16: /** 17: * @defgroup ntt_fft_params ntt_fft_params 18: * @{ @ingroup ntt_p 19: */ 20: 21: #ifndef NTT_FFT_PARAMS_H_ 22: #define NTT_FFT_PARAMS_H_ 23: 24: #include <library.h> 25: 26: typedef struct ntt_fft_params_t ntt_fft_params_t; 27: 28: /** 29: * Defines the parameters for an NTT computed via the FFT algorithm 30: */ 31: struct ntt_fft_params_t { 32: 33: /** 34: * Prime modulus 35: */ 36: uint16_t q; 37: 38: /** 39: * Inverse of Prime modulus (-q_inv * q mod r = 1) 40: */ 41: uint16_t q_inv; 42: 43: /** 44: * Logarithm of Montgomery radix: log2(r) 45: */ 46: uint16_t rlog; 47: 48: /** 49: * Square of Montgomery radix: r^2 mod q 50: */ 51: const uint32_t r2; 52: 53: /** 54: * Montgomery radix mask: (1<<rlog) - 1 55: */ 56: const uint32_t rmask; 57: 58: /** 59: * Size of the FFT with the condition k * n = q-1 60: */ 61: const uint16_t n; 62: 63: /** 64: * Inverse of n mod q used for normalization of the FFT 65: */ 66: const uint16_t n_inv; 67: 68: /** 69: * Number of FFT stages stages = log2(n) 70: */ 71: const uint16_t stages; 72: 73: /** 74: * FFT twiddle factors (n-th roots of unity) in Montgomery form 75: */ 76: const uint16_t *wr; 77: 78: /** 79: * FFT phase shift (2n-th roots of unity) in forward transform 80: */ 81: const uint16_t *wf; 82: 83: /** 84: * FFT phase shift (2n-th roots of unity) and scaling in inverse transform 85: */ 86: const uint16_t *wi; 87: 88: /** 89: * Subsampling of FFT twiddle factors table 90: */ 91: const uint16_t s; 92: 93: /** 94: * FFT bit reversal 95: */ 96: const uint16_t *rev; 97: 98: }; 99: 100: /** 101: * FFT parameters for q = 12289 and n = 1024 102: */ 103: extern const ntt_fft_params_t ntt_fft_12289_1024; 104: 105: /** 106: * FFT parameters for q = 12289 and n = 512 107: */ 108: extern const ntt_fft_params_t ntt_fft_12289_512; 109: 110: /** 111: * FFT parameters for q = 17 and n = 8 112: */ 113: extern const ntt_fft_params_t ntt_fft_17_8; 114: 115: #endif /** NTT_FFT_PARAMS_H_ @}*/