Edit

kc3-lang/libtommath/bn_prime_sizes_tab.c

Branch :

  • Show log

    Commit

  • Author : Tom St Denis
    Date : 2004-01-25 17:40:21
    Hash : 6c48a9b3
    Message : added libtommath-0.29

  • bn_prime_sizes_tab.c
  • /* LibTomMath, multiple-precision integer library -- Tom St Denis
     *
     * LibTomMath is a library that provides multiple-precision
     * integer arithmetic as well as number theoretic functionality.
     *
     * The library was designed directly after the MPI library by
     * Michael Fromberger but has been written from scratch with
     * additional optimizations in place.
     *
     * The library is free for all purposes without any express
     * guarantee it works.
     *
     * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
     */
    #include <tommath.h>
    
    /* this table gives the # of rabin miller trials for a prob of failure lower than 2^-96 */
    static const struct {
       int k, t;
    } sizes[] = {
    {   128,    28 },
    {   256,    16 },
    {   384,    10 },
    {   512,     7 },
    {   640,     6 },
    {   768,     5 },
    {   896,     4 },
    {  1024,     4 },
    {  1152,     3 },
    {  1280,     3 },
    {  1408,     3 },
    {  1536,     3 },
    {  1664,     3 },
    {  1792,     2 } };
    
    /* returns # of RM trials required for a given bit size */
    int mp_prime_rabin_miller_trials(int size)
    {
       int x;
    
       for (x = 0; x < (int)(sizeof(sizes)/(sizeof(sizes[0]))); x++) {
           if (sizes[x].k == size) {
              return sizes[x].t;
           } else if (sizes[x].k > size) {
              return (x == 0) ? sizes[0].t : sizes[x - 1].t;
           }
       }
       return 1;
    }