示例#1
0
void miller(element_t res, mpz_t q, element_t P, element_ptr Qx, element_ptr Qy) {
  int m;
  element_t v;
  element_t Z;
  element_t a, b, c;
  element_t t0;
  element_t e0;
  const element_ptr cca = curve_a_coeff(P);
  const element_ptr Px = curve_x_coord(P);
  const element_ptr Py = curve_y_coord(P);
  element_ptr Zx, Zy;

  void do_tangent(void) {
    // a = -(3 Zx^2 + cc->a)
    // b = 2 * Zy
    // c = -(2 Zy^2 + a Zx);

    element_square(a, Zx); mult1++;
    element_mul_si(a, a, 3); add1++; add1++; add1++;
    element_add(a, a, cca); add1++;
    element_neg(a, a);

    element_add(b, Zy, Zy); add1++;

    element_mul(t0, b, Zy); mult1++;
    element_mul(c, a, Zx); mult1++;
    element_add(c, c, t0); add1++;
    element_neg(c, c);

    d_miller_evalfn(e0, a, b, c, Qx, Qy);
    element_mul(v, v, e0); multk++;
  }
示例#2
0
文件: d_param.c 项目: blynn/pbc
static void d_pairing_pp_apply(element_ptr out, element_ptr in2,
    pairing_pp_t p) {
  mpz_ptr q = p->pairing->r;
  pptr info = p->pairing->data;
  mp_bitcnt_t m = (mp_bitcnt_t)mpz_sizeinbase(q, 2);
  m = (m > 2 ? m - 2 : 0);
  pp_coeff_t *coeff = (pp_coeff_t *) p->data;
  pp_coeff_ptr pp = coeff[0];
  element_ptr Qbase = in2;
  element_t e0;
  element_t Qx, Qy;
  element_t v;
  element_init_same_as(e0, out);
  element_init_same_as(v, out);
  element_init(Qx, info->Fqd);
  element_init(Qy, info->Fqd);

  // Twist: (x, y) --> (v^-1 x, v^-(3/2) y)
  // where v is the quadratic nonresidue used to construct the twist
  element_mul(Qx, curve_x_coord(Qbase), info->nqrinv);
  // v^-3/2 = v^-2 * v^1/2
  element_mul(Qy, curve_y_coord(Qbase), info->nqrinv2);

  element_set1(out);
  for(;;) {
    d_miller_evalfn(e0, pp->a, pp->b, pp->c, Qx, Qy);
    element_mul(out, out, e0);
    pp++;

    if (!m) break;

    if (mpz_tstbit(q, m)) {
      d_miller_evalfn(e0, pp->a, pp->b, pp->c, Qx, Qy);
      element_mul(out, out, e0);
      pp++;
    }
    m--;
    element_square(out, out);
  }
  cc_tatepower(out, out, p->pairing);

  element_clear(e0);
  element_clear(Qx);
  element_clear(Qy);
  element_clear(v);
}
示例#3
0
  void do_line(void) {
    // a = -(B.y - A.y) / (B.x - A.x);
    // b = 1;
    // c = -(A.y + a * A.x);
    // but we multiply by B.x - A.x to avoid division.

    element_sub(b, Px, Zx); add1++;
    element_sub(a, Zy, Py); add1++;
    element_mul(t0, b, Zy); mult1++;
    element_mul(c, a, Zx); mult1++;
    element_add(c, c, t0); add1++;
    element_neg(c, c);

    d_miller_evalfn(e0, a, b, c, Qx, Qy);
    element_mul(v, v, e0); multk++;
  }