example/zss.c

   1 /*
   2   ZSS Short Signature Scheme from Bilinear Pairing.
   3   Based on papers "F. Zhang, R. Safavi-Naini and W. Susilo. An Efficient Signature Scheme from Bilinear Pairings and it's Applications. PKC 2004".
   4   Contributed by Dmitry Kosolapov.
   5 */
   6
   7 #include <pbc.h>
   8 #include <pbc_test.h>
   9
  10 int main(int argc, char **argv) {
  11   pairing_t pairing;
  12   pbc_demo_pairing_init(pairing, argc, argv);
  13   if (!pairing_is_symmetric(pairing)) pbc_die("pairing must be symmetric");
  14   double time1, time2;
  15   element_t P, Ppub, x, S, H, t1, t2, t3, t4;
  16   element_init_Zr(x, pairing);
  17   element_init_Zr(H, pairing);
  18   element_init_Zr(t1, pairing);
  19
  20   element_init_G1(S, pairing);
  21   element_init_G1(P, pairing);
  22   element_init_G1(Ppub, pairing);
  23   element_init_G1(t2, pairing);
  24
  25   element_init_GT(t3, pairing);
  26   element_init_GT(t4, pairing);
  27
  28   printf("ZSS short signature schema\n");
  29   printf("KEYGEN\n");
  30   time1 = pbc_get_time();
  31   element_random(x);
  32   element_random(P);
  33   element_mul_zn(Ppub, P, x);
  34   element_printf("P = %B\n", P);
  35   element_printf("x = %B\n", x);
  36   element_printf("Ppub = %B\n", Ppub);
  37
  38   printf("SIGN\n");
  39   element_from_hash(H, "Message", 7);
  40   element_add(t1, H, x);
  41   element_invert(t1, t1);
  42   element_mul_zn(S, P, t1);
  43   printf("Signature of message \"Message\" is:\n");
  44   element_printf("S = %B\n", S);
  45
  46   printf("VERIFY\n");
  47   element_from_hash(H, "Message", 7);
  48   element_mul_zn(t2, P, H);
  49   element_add(t2, t2, Ppub);
  50   element_pairing(t3, t2, S);
  51   element_pairing(t4, P, P);
  52   element_printf("e(H(m)P + Ppub, S) = %B\n", t3);
  53   element_printf("e(P, P) = %B\n", t4);
  54   if (!element_cmp(t3, t4)) printf("Signature is valid\n");
  55   else printf("Signature is invalid\n");
  56   time2 = pbc_get_time();
  57   printf("All time = %fs\n", time2 - time1);
  58   element_clear(P);
  59   element_clear(Ppub);
  60   element_clear(x);
  61   element_clear(S);
  62   element_clear(H);
  63   element_clear(t1);
  64   element_clear(t2);
  65   element_clear(t3);
  66   element_clear(t4);
  67   pairing_clear(pairing);
  68
  69   return 0;
  70 }