3 * $Id: rabin.h,v 1.6 2002/01/13 13:42:53 mdw Exp $
5 * Miller-Rabin primality test
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
14 * Catacomb is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
19 * Catacomb is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
24 * You should have received a copy of the GNU Library General Public
25 * License along with Catacomb; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.6 2002/01/13 13:42:53 mdw
34 * More efficient Rabin-Miller test: with random witnesses, skip redundant
35 * Montgomerization. (Being bijective, it can't affect the distribution.)
37 * Revision 1.5 2000/07/09 21:32:16 mdw
38 * rabin_test: Correct error in comment.
40 * Revision 1.4 2000/06/17 11:52:48 mdw
43 * Revision 1.3 1999/12/22 15:50:29 mdw
44 * Reworking for new prime-search system. Add function for working out how
45 * many iterations to use for a particular number.
47 * Revision 1.2 1999/12/10 23:29:48 mdw
48 * Change header file guard names.
50 * Revision 1.1 1999/11/19 13:17:57 mdw
51 * Prime number generator and tester.
55 #ifndef CATACOMB_RABIN_H
56 #define CATACOMB_RABIN_H
62 /*----- Header files ------------------------------------------------------*/
68 #ifndef CATACOMB_MPMONT_H
72 #ifndef CATACOMB_PFILT_H
76 /*----- Data structures ---------------------------------------------------*/
78 typedef struct rabin
{
79 mpmont mm
; /* Montgomery arithmetic context */
80 size_t s
; /* %$m = 2^s r + 1$% */
81 mp
*r
; /* %$m = 2^s r + 1$% */
82 mp
*m1
; /* %$(m - 1)R \bmod m$% */
85 /*----- Functions provided ------------------------------------------------*/
87 /* --- @rabin_create@ --- *
89 * Arguments: @rabin *r@ = pointer to Rabin-Miller context
90 * @mp *m@ = pointer to number to test
94 * Use: Precomputes some useful values for performing the
95 * Miller-Rabin probabilistic primality test.
98 extern void rabin_create(rabin */
*r*/
, mp */
*m*/
);
100 /* --- @rabin_destroy@ --- *
102 * Arguments: @rabin *r@ = pointer to Rabin-Miller context
106 * Use: Disposes of a Rabin-Miller context when it's no longer
110 extern void rabin_destroy(rabin */
*r*/
);
112 /* --- @rabin_test@, @rabin_rtest@ --- *
114 * Arguments: @rabin *r@ = pointer to Rabin-Miller context
115 * @mp *g@ = base to test the number against
117 * Returns: Either @PGEN_FAIL@ if the test failed, or @PGEN_PASS@
120 * Use: Performs a single iteration of the Rabin-Miller primality
121 * test. The @rtest@ variant assumes that %$g$% is either
122 * already in Montgomery representation, or you don't care.
125 extern int rabin_rtest(rabin */
*r*/
, mp */
*g*/
);
126 extern int rabin_test(rabin */
*r*/
, mp */
*g*/
);
128 /* --- @rabin_iters@ --- *
130 * Arguments: @unsigned len@ = number of bits in value
132 * Returns: Number of iterations recommended.
134 * Use: Returns the recommended number of iterations to ensure that a
135 * number with @len@ bits is really prime.
138 extern int rabin_iters(unsigned /*len*/);
140 /*----- That's all, folks -------------------------------------------------*/