diff options
author | WuKong <rebirthmonkey@gmail.com> | 2015-09-04 09:25:34 +0200 |
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committer | WuKong <rebirthmonkey@gmail.com> | 2015-09-04 09:25:34 +0200 |
commit | 3baeb11a8fbcfcdbc31976d421f17b85503b3ecd (patch) | |
tree | 04891d88c1127148f1b390b5a24414e85b270aee /moon-abe/pbc-0.5.14/ecc/hilbert.c | |
parent | 67c5b73910f5fc437429c356978081b252a59480 (diff) |
init attribute-based encryption
Change-Id: Iba1a3d722110abf747a0fba366f3ebc911d25b25
Diffstat (limited to 'moon-abe/pbc-0.5.14/ecc/hilbert.c')
-rw-r--r-- | moon-abe/pbc-0.5.14/ecc/hilbert.c | 539 |
1 files changed, 539 insertions, 0 deletions
diff --git a/moon-abe/pbc-0.5.14/ecc/hilbert.c b/moon-abe/pbc-0.5.14/ecc/hilbert.c new file mode 100644 index 00000000..753e70e0 --- /dev/null +++ b/moon-abe/pbc-0.5.14/ecc/hilbert.c @@ -0,0 +1,539 @@ +#include <stdarg.h> +#include <stdio.h> +#include <stdint.h> // for intptr_t +#include <stdlib.h> //for pbc_malloc, pbc_free +#include <gmp.h> +#include <math.h> +#include "pbc_utils.h" +#include "pbc_field.h" +#include "pbc_poly.h" +#include "pbc_hilbert.h" +#include "pbc_memory.h" + +#include "misc/darray.h" +#include "mpc.h" + +static mpf_t pi, eulere, recipeulere, epsilon, negepsilon; + +static void mpf_exp(mpf_t res, mpf_t pwr) { + mpf_t a; + mpf_t f0; + int i; + + mpf_init(a); mpf_set(a, pwr); + + mpf_init(f0); + + mpf_set(f0, a); + mpf_add_ui(res, a, 1); + + for (i=2;;i++) { + mpf_mul(f0, f0, a); + mpf_div_ui(f0, f0, i); + if (mpf_sgn(f0) > 0) { + if (mpf_cmp(f0, epsilon) < 0) break; + } else { + if (mpf_cmp(f0, negepsilon) > 0) break; + } + mpf_add(res, res, f0); + } + + mpf_clear(f0); + mpf_clear(a); +} + +static void mpc_cis(mpc_t res, mpf_t theta) { + mpf_t a; + + mpf_init(a); mpf_set(a, theta); + //res = exp(i a) + // = cos a + i sin a + //converges quickly near the origin + mpf_t f0; + mpf_ptr rx = mpc_re(res), ry = mpc_im(res); + int i; + int toggle = 1; + + mpf_init(f0); + + mpf_set(f0, a); + mpf_set_ui(rx, 1); + mpf_set(ry, f0); + i = 1; + for(;;) { + toggle = !toggle; + i++; + mpf_div_ui(f0, f0, i); + mpf_mul(f0, f0, a); + if (toggle) { + mpf_add(rx, rx, f0); + } else { + mpf_sub(rx, rx, f0); + } + + i++; + mpf_div_ui(f0, f0, i); + mpf_mul(f0, f0, a); + + if (toggle) { + mpf_add(ry, ry, f0); + } else { + mpf_sub(ry, ry, f0); + } + + if (mpf_sgn(f0) > 0) { + if (mpf_cmp(f0, epsilon) < 0) break; + } else { + if (mpf_cmp(f0, negepsilon) > 0) break; + } + } + + mpf_clear(f0); + mpf_clear(a); +} + +// Computes q = exp(2 pi i tau). +static void compute_q(mpc_t q, mpc_t tau) { + mpc_t z0; + mpf_t f0, f1; + mpf_ptr fp0; + unsigned long pwr; + + mpc_init(z0); + mpf_init(f0); + mpf_init(f1); + + //compute z0 = 2 pi i tau + mpc_set(z0, tau); + //first remove integral part of Re(tau) + //since exp(2 pi i) = 1 + //it seems |Re(tau)| < 1 anyway? + fp0 = mpc_re(z0); + mpf_trunc(f1, fp0); + mpf_sub(fp0, fp0, f1); + + mpc_mul_mpf(z0, z0, pi); + mpc_mul_ui(z0, z0, 2); + mpc_muli(z0, z0); + + //compute q = exp(z0); + //first write z0 = A + a + b i + //where A is a (negative) integer + //and a, b are in [-1, 1] + //compute e^A separately + fp0 = mpc_re(z0); + pwr = mpf_get_ui(fp0); + mpf_pow_ui(f0, recipeulere, pwr); + mpf_add_ui(fp0, fp0, pwr); + + mpf_exp(f1, mpc_re(z0)); + mpf_mul(f0, f1, f0); + mpc_cis(q, mpc_im(z0)); + + /* + old_mpc_exp(q, z0); + */ + mpc_mul_mpf(q, q, f0); + + mpc_clear(z0); + mpf_clear(f0); + mpf_clear(f1); +} + +// Computes z = Delta(q) (see Cohen). +static void compute_Delta(mpc_t z, mpc_t q) { + int d; + int n; + int power; + mpc_t z0, z1, z2; + + mpc_init(z0); + mpc_init(z1); + mpc_init(z2); + + mpc_set_ui(z0, 1); + d = -1; + for(n=1; n<100; n++) { + power = n *(3 * n - 1) / 2; + mpc_pow_ui(z1, q, power); + mpc_pow_ui(z2, q, n); + mpc_mul(z2, z2, z1); + mpc_add(z1, z1, z2); + if (d) { + mpc_sub(z0, z0, z1); + d = 0; + } else { + mpc_add(z0, z0, z1); + d = 1; + } + } + + mpc_pow_ui(z0, z0, 24); + mpc_mul(z, z0, q); + + mpc_clear(z0); + mpc_clear(z1); + mpc_clear(z2); +} + +// Computes z = h(tau) +// (called h() by Blake et al, f() by Cohen.) +static void compute_h(mpc_t z, mpc_t tau) { + mpc_t z0, z1, q; + mpc_init(q); + mpc_init(z0); + mpc_init(z1); + compute_q(q, tau); + mpc_mul(z0, q, q); + compute_Delta(z0, z0); + compute_Delta(z1, q); + mpc_div(z, z0, z1); + mpc_clear(q); + mpc_clear(z0); + mpc_clear(z1); +} + +// Computes j = j(tau). +static void compute_j(mpc_t j, mpc_t tau) { + mpc_t h; + mpc_t z0; + mpc_init(h); + mpc_init(z0); + compute_h(h, tau); + //mpc_mul_ui(z0, h, 256); + mpc_mul_2exp(z0, h, 8); + mpc_add_ui(z0, z0, 1); + mpc_pow_ui(z0, z0, 3); + mpc_div(j, z0, h); + mpc_clear(z0); + mpc_clear(h); +} + +static void compute_pi(int prec) { + //Chudnovsky brothers' Ramanujan formula + //http://www.cs.uwaterloo.ca/~alopez-o/math-faq/mathtext/node12.html + mpz_t k1, k2, k4, k5, d; + unsigned int k3 = 640320; + unsigned int k6 = 53360; + mpz_t z0, z1, z2; + mpq_t p, q; + mpf_t f1; + int toggle = 1; + int n; + //converges fast: each term gives over 47 bits + int nlimit = prec / 47 + 1; + + mpz_init(k1); + mpz_init(k2); + mpz_init(k4); + mpz_init(k5); + mpz_init(d); + mpz_init(z0); + mpz_init(z1); + mpz_init(z2); + mpq_init(q); + mpq_init(p); + mpf_init(f1); + + mpz_set_str(k1, "545140134", 10); + mpz_set_str(k2, "13591409", 10); + mpz_set_str(k4, "100100025", 10); + mpz_set_str(k5, "327843840", 10); + + mpz_mul(d, k4, k5); + mpz_mul_2exp(d, d, 3); + mpq_set_ui(p, 0, 1); + + for (n=0; n<nlimit; n++) { + mpz_fac_ui(z0, 6*n); + mpz_mul_ui(z1, k1, n); + mpz_add(z1, z1, k2); + mpz_mul(z0, z0, z1); + + mpz_fac_ui(z1, 3*n); + mpz_fac_ui(z2, n); + mpz_pow_ui(z2, z2, 3); + mpz_mul(z1, z1, z2); + mpz_pow_ui(z2, d, n); + mpz_mul(z1, z1, z2); + + mpz_set(mpq_numref(q), z0); + mpz_set(mpq_denref(q), z1); + mpq_canonicalize(q); + if (toggle) { + mpq_add(p, p, q); + } else { + mpq_sub(p, p, q); + } + toggle = !toggle; + } + mpq_inv(q, p); + mpz_mul_ui(mpq_numref(q), mpq_numref(q), k6); + mpq_canonicalize(q); + mpf_set_q(pi, q); + mpf_sqrt_ui(f1, k3); + mpf_mul(pi, pi, f1); + //mpf_out_str(stdout, 0, 14 * nlimit, pi); + //printf("\n"); + + mpz_clear(k1); + mpz_clear(k2); + mpz_clear(k4); + mpz_clear(k5); + mpz_clear(d); + mpz_clear(z0); + mpz_clear(z1); + mpz_clear(z2); + mpq_clear(q); + mpq_clear(p); + mpf_clear(f1); +} + +static void precision_init(int prec) { + int i; + mpf_t f0; + + mpf_set_default_prec(prec); + mpf_init2(epsilon, 2); + mpf_init2(negepsilon, 2); + mpf_init(recipeulere); + mpf_init(pi); + mpf_init(eulere); + + mpf_set_ui(epsilon, 1); + mpf_div_2exp(epsilon, epsilon, prec); + mpf_neg(negepsilon, epsilon); + + mpf_init(f0); + mpf_set_ui(eulere, 1); + mpf_set_ui(f0, 1); + for (i=1;; i++) { + mpf_div_ui(f0, f0, i); + if (mpf_cmp(f0, epsilon) < 0) { + break; + } + mpf_add(eulere, eulere, f0); + } + mpf_clear(f0); + + mpf_ui_div(recipeulere, 1, eulere); + + compute_pi(prec); +} + +static void precision_clear(void) { + mpf_clear(eulere); + mpf_clear(recipeulere); + mpf_clear(pi); + mpf_clear(epsilon); + mpf_clear(negepsilon); +} + +// See Cohen; my D is -D in his notation. +size_t pbc_hilbert(mpz_t **arr, int D) { + int a, b; + int t; + int B = floor(sqrt((double) D / 3.0)); + mpc_t alpha; + mpc_t j; + mpf_t sqrtD; + mpf_t f0; + darray_t Pz; + mpc_t z0, z1, z2; + double d = 1.0; + int h = 1; + int jcount = 1; + + // Compute required precision. + b = D % 2; + for (;;) { + t = (b*b + D) / 4; + a = b; + if (a <= 1) { + a = 1; + goto step535_4; + } +step535_3: + if (!(t % a)) { + jcount++; + if ((a == b) || (a*a == t) || !b) { + d += 1.0 / ((double) a); + h++; + } else { + d += 2.0 / ((double) a); + h+=2; + } + } +step535_4: + a++; + if (a * a <= t) { + goto step535_3; + } else { + b += 2; + if (b > B) break; + } + } + + //printf("modulus: %f\n", exp(3.14159265358979 * sqrt(D)) * d * 0.5); + d *= sqrt(D) * 3.14159265358979 / log(2); + precision_init(d + 34); + pbc_info("class number %d, %d bit precision", h, (int) d + 34); + + darray_init(Pz); + mpc_init(alpha); + mpc_init(j); + mpc_init(z0); + mpc_init(z1); + mpc_init(z2); + mpf_init(sqrtD); + mpf_init(f0); + + mpf_sqrt_ui(sqrtD, D); + b = D % 2; + h = 0; + for (;;) { + t = (b*b + D) / 4; + if (b > 1) { + a = b; + } else { + a = 1; + } +step3: + if (t % a) { +step4: + a++; + if (a * a <= t) goto step3; + } else { + // a, b, t/a are coeffs of an appropriate primitive reduced positive + // definite form. + // Compute j((-b + sqrt{-D})/(2a)). + h++; + pbc_info("[%d/%d] a b c = %d %d %d", h, jcount, a, b, t/a); + mpf_set_ui(f0, 1); + mpf_div_ui(f0, f0, 2 * a); + mpf_mul(mpc_im(alpha), sqrtD, f0); + mpf_mul_ui(f0, f0, b); + mpf_neg(mpc_re(alpha), f0); + + compute_j(j, alpha); +if (0) { + int i; + for (i=Pz->count - 1; i>=0; i--) { + printf("P %d = ", i); + mpc_out_str(stdout, 10, 4, Pz->item[i]); + printf("\n"); + } +} + if (a == b || a * a == t || !b) { + // P *= X - j + int i, n; + mpc_ptr p0; + p0 = (mpc_ptr) pbc_malloc(sizeof(mpc_t)); + mpc_init(p0); + mpc_neg(p0, j); + n = Pz->count; + if (n) { + mpc_set(z1, Pz->item[0]); + mpc_add(Pz->item[0], z1, p0); + for (i=1; i<n; i++) { + mpc_mul(z0, z1, p0); + mpc_set(z1, Pz->item[i]); + mpc_add(Pz->item[i], z1, z0); + } + mpc_mul(p0, p0, z1); + } + darray_append(Pz, p0); + } else { + // P *= X^2 - 2 Re(j) X + |j|^2 + int i, n; + mpc_ptr p0, p1; + p0 = (mpc_ptr) pbc_malloc(sizeof(mpc_t)); + p1 = (mpc_ptr) pbc_malloc(sizeof(mpc_t)); + mpc_init(p0); + mpc_init(p1); + // p1 = - 2 Re(j) + mpf_mul_ui(f0, mpc_re(j), 2); + mpf_neg(f0, f0); + mpf_set(mpc_re(p1), f0); + // p0 = |j|^2 + mpf_mul(f0, mpc_re(j), mpc_re(j)); + mpf_mul(mpc_re(p0), mpc_im(j), mpc_im(j)); + mpf_add(mpc_re(p0), mpc_re(p0), f0); + n = Pz->count; + if (!n) { + } else if (n == 1) { + mpc_set(z1, Pz->item[0]); + mpc_add(Pz->item[0], z1, p1); + mpc_mul(p1, z1, p1); + mpc_add(p1, p1, p0); + mpc_mul(p0, p0, z1); + } else { + mpc_set(z2, Pz->item[0]); + mpc_set(z1, Pz->item[1]); + mpc_add(Pz->item[0], z2, p1); + mpc_mul(z0, z2, p1); + mpc_add(Pz->item[1], z1, z0); + mpc_add(Pz->item[1], Pz->item[1], p0); + for (i=2; i<n; i++) { + mpc_mul(z0, z1, p1); + mpc_mul(alpha, z2, p0); + mpc_set(z2, z1); + mpc_set(z1, Pz->item[i]); + mpc_add(alpha, alpha, z0); + mpc_add(Pz->item[i], z1, alpha); + } + mpc_mul(z0, z2, p0); + mpc_mul(p1, p1, z1); + mpc_add(p1, p1, z0); + mpc_mul(p0, p0, z1); + } + darray_append(Pz, p1); + darray_append(Pz, p0); + } + goto step4; + } + b+=2; + if (b > B) break; + } + + // Round polynomial and assign. + int k = 0; + { + *arr = pbc_malloc(sizeof(mpz_t) * (Pz->count + 1)); + int i; + for (i=Pz->count - 1; i>=0; i--) { + if (mpf_sgn(mpc_re(Pz->item[i])) < 0) { + mpf_set_d(f0, -0.5); + } else { + mpf_set_d(f0, 0.5); + } + mpf_add(f0, f0, mpc_re(Pz->item[i])); + mpz_init((*arr)[k]); + mpz_set_f((*arr)[k], f0); + k++; + mpc_clear(Pz->item[i]); + pbc_free(Pz->item[i]); + } + mpz_init((*arr)[k]); + mpz_set_ui((*arr)[k], 1); + k++; + } + darray_clear(Pz); + mpc_clear(z0); + mpc_clear(z1); + mpc_clear(z2); + mpf_clear(f0); + mpf_clear(sqrtD); + mpc_clear(alpha); + mpc_clear(j); + + precision_clear(); + return k; +} + +void pbc_hilbert_free(mpz_t *arr, size_t n) { + size_t i; + + for (i = 0; i < n; i++) mpz_clear(arr[i]); + pbc_free(arr); +} |