63 lines
1.7 KiB
C
63 lines
1.7 KiB
C
/*
|
||
* Copyright (C) 2014 FH Bielefeld
|
||
*
|
||
* This file is part of a FH Bielefeld project.
|
||
*
|
||
* This library is free software; you can redistribute it and/or
|
||
* modify it under the terms of the GNU Lesser General Public
|
||
* License as published by the Free Software Foundation; either
|
||
* version 2.1 of the License, or (at your option) any later version.
|
||
*
|
||
* This library is distributed in the hope that it will be useful,
|
||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
* Lesser General Public License for more details.
|
||
*
|
||
* You should have received a copy of the GNU Lesser General Public
|
||
* License along with this library; if not, write to the Free Software
|
||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
|
||
* MA 02110-1301 USA
|
||
*/
|
||
|
||
/**
|
||
* @file encrypt.c
|
||
* This file handles the NTRU encryption
|
||
* algorithm.
|
||
* @brief NTRU encryption
|
||
*/
|
||
|
||
#include "encrypt.h"
|
||
|
||
#include <fmpz_poly.h>
|
||
#include <fmpz.h>
|
||
|
||
|
||
/**
|
||
* encrypt the msg, using the math:
|
||
* e = (h ∗ r) + m (mod q)
|
||
*
|
||
* e = the encrypted poly
|
||
* h = the public key
|
||
* r = the random poly
|
||
* m = the message poly
|
||
* q = large mod
|
||
*
|
||
* @param msg pb_poly* the message to encrypt
|
||
* @param pub_key pb_poly* the public key
|
||
* @param rnd pb_poly* the random poly
|
||
* @param out pb_poly* the output poly [out]
|
||
* @param ctx ntru_context* the ntru context
|
||
*/
|
||
void ntru_encrypt_poly(
|
||
fmpz_poly_t msg,
|
||
fmpz_poly_t pub_key,
|
||
fmpz_poly_t rnd,
|
||
fmpz_poly_t out,
|
||
ntru_context *ctx)
|
||
{
|
||
fmpz_poly_zero(out);
|
||
poly_starmultiply(pub_key, rnd, out, ctx, ctx->q);
|
||
fmpz_poly_add(out, out, msg);
|
||
fmpz_poly_mod_unsigned(out, ctx->q);
|
||
}
|