96 lines
2.6 KiB
C
96 lines
2.6 KiB
C
/*
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* Copyright (C) 2014 Andreas Steffen
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*
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* Copyright (C) secunet Security Networks AG
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*/
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/**
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* @defgroup bliss_sampler bliss_sampler
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* @{ @ingroup bliss_p
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*/
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#ifndef BLISS_SAMPLER_H_
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#define BLISS_SAMPLER_H_
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typedef struct bliss_sampler_t bliss_sampler_t;
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#include "bliss_param_set.h"
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#include <library.h>
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#include <crypto/hashers/hasher.h>
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/**
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* Implementation various rejection sampling algorithms.
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*/
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struct bliss_sampler_t {
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/**
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* Sample according to exp(-x/(2*sigma^2))
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*
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* @param x Value to be sampled
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* @param accepted TRUE if value is accepted, FALSE if rejected
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* @result TRUE if sampling was successful
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*/
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bool (*bernoulli_exp)(bliss_sampler_t *this, uint32_t x, bool *accepted);
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/**
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* Sample according to 1/cosh(x/sigma^2)
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*
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* @param x Value to be sampled
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* @param accepted TRUE if value is accepted, FALSE if rejected
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* @result TRUE if sampling was successful
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*/
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bool (*bernoulli_cosh)(bliss_sampler_t *this, int32_t x, bool *accepted);
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/**
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* Sample according to 2^(-x^2) for positive x
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*
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* @param x Generated value
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* @result TRUE if sampling was successful
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*/
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bool (*pos_binary)(bliss_sampler_t *this, uint32_t *x);
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/**
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* Sample according to the Gaussian distribution exp(-x^2/(2*sigma^2))
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*
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* @param z Generated value with Gaussian distribution
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* @result TRUE if sampling was successful
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*/
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bool (*gaussian)(bliss_sampler_t *this, int32_t *z);
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/**
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* Sample the sign according to the binary distribution
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*
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* @param positive TRUE if positive
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* @result TRUE if sampling was successful
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*/
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bool (*sign)(bliss_sampler_t *this, bool *positive);
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/**
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* Destroy bliss_sampler_t object
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*/
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void (*destroy)(bliss_sampler_t *this);
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};
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/**
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* Create a bliss_sampler_t object.
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*
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* @param alg XOF to be used for the internal bitspender
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* @param seed Seed used to initialize the internal bitspender
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* @param set BLISS parameter set to be used
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*/
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bliss_sampler_t *bliss_sampler_create(ext_out_function_t alg, chunk_t seed,
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const bliss_param_set_t *set);
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#endif /** BLISS_SAMPLER_H_ @}*/
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