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/* Makes safe primes of a 2k nature */
#include <tommath.h>
#include <time.h>
int sizes[] = {256, 512, 768, 1024, 1536, 2048, 3072, 4096};
int main(void)
{
char buf[2000];
int x, y;
mp_int q, p;
FILE *out;
clock_t t1;
mp_digit z;
mp_init_multi(&q, &p, NULL);
out = fopen("2kprime.1", "w");
for (x = 0; x < (int)(sizeof(sizes) / sizeof(sizes[0])); x++) {
top:
mp_2expt(&q, sizes[x]);
mp_add_d(&q, 3, &q);
z = -3;
t1 = clock();
for(;;) {
mp_sub_d(&q, 4, &q);
z += 4;
if (z > MP_MASK) {
printf("No primes of size %d found\n", sizes[x]);
break;
}
if (clock() - t1 > CLOCKS_PER_SEC) {
printf("."); fflush(stdout);
// sleep((clock() - t1 + CLOCKS_PER_SEC/2)/CLOCKS_PER_SEC);
t1 = clock();
}
/* quick test on q */
mp_prime_is_prime(&q, 1, &y);
if (y == 0) {
continue;
}
/* find (q-1)/2 */
mp_sub_d(&q, 1, &p);
mp_div_2(&p, &p);
mp_prime_is_prime(&p, 3, &y);
if (y == 0) {
continue;
}
/* test on q */
mp_prime_is_prime(&q, 3, &y);
if (y == 0) {
continue;
}
break;
}
if (y == 0) {
++sizes[x];
goto top;
}
mp_toradix(&q, buf, 10);
printf("\n\n%d-bits (k = %lu) = %s\n", sizes[x], z, buf);
fprintf(out, "%d-bits (k = %lu) = %s\n", sizes[x], z, buf); fflush(out);
}
return 0;
}
/* $Source$ */
/* $Revision$ */
/* $Date$ */