Commit a462f537af43fe136e28a5a75a7128697904b4ef

geremy condra
Sun Oct 18 09:10:24 CEST 2009

Tree SHA1: 3b7df22
Parent SHA1: be96115 (FEATURES: added get_random_prime() to pypbc; adding example cryptosytem)
raw diff | raw patch

FEATURE: added get_random, which selects an int from a given range randomly

Also made minor progress on KSW

Diff rendering mode:
inline
side by side


52	52
53	53	def __init__(self, i) -> "(PK, SK)":
54	54	# select p, q, r
	55	p = get_random_prime(200)
	56	q = get_random_prime(200)
	57	r = get_random_prime(200)
55	58	# make n
	59	n = pqr
56	60	# build the params
	61	self.params = Parameters(n=n)
57	62	# build the pairing
	63	self.pairing = Pairing(params)
58	64	# find the generators for the G_p, G_q, and G_r subgroups
	65	self.g_G = Element.random(pairing, G1)**n
	66	self.g_G_p = Element.random(pairing, G1)*(qr)
	67	self.g_G_r = Element.random(pairing, G1)*(pq)
	68	self.g_G_q = Element.random(pairing, G1)*(pr)
59	69	# choose R0
	70	self.R0 = self.g_G_r ** get_random(r)
60	71	# choose the random R's
61	72	# choose the random H's
62	73	# calculate Q


20	20	mpz_init_set_str(new_n, n_char, 10);
21	21	}
22	22
	23	PyObject *mpz_to_pynum(mpz_t n) {
	24	// get the mpz as a string
	25	char *s = mpz_get_str(NULL, 10, n);
	26
	27	// convert the string to a python long
	28	PyObject *l = PyLong_FromString(s, NULL, 10);
	29
	30	// clean up
	31	free(s);
	32
	33	// return it
	34	return l;
	35	}
	36
23	37	PyObject get_random_prime(PyObject self, PyObject *args) {
24	38	// gets the number of bits from the args
25	39	int num_bits;
…	…
43	43	}
44	44
45	45	// create the storage number
46		mpz_t c, p;
47		mpz_init(c);
	46	mpz_t p;
48	47	mpz_init(p);
49	48
50	49	// get a random n-bit number
51		pbc_mpz_randomb(c, num_bits);
	50	pbc_mpz_randomb(p, num_bits);
52	51
53	52	// get the next prime
54		mpz_nextprime(p, c);
	53	mpz_nextprime(p, p);
55	54
56	55	// get the mpz as a string
57		char *str_prime = mpz_get_str(NULL, 10, p);
	56	PyObject *rand_prime = mpz_to_pynum(p);
58	57
59		// convert the string to a python long
60		PyObject *rand_prime = PyLong_FromString(str_prime, NULL, 10);
61
62	58	// clean up the mpz's
63		mpz_clear(c);
64	59	mpz_clear(p);
65	60
66		// clean up the str
67		free(str_prime);
68	61	return rand_prime;
69	62	}
70	63
	64	PyObject get_random(PyObject self, PyObject *args) {
	65	// gets the number of bits from the args
	66	PyObject *max;
	67	if (!PyArg_ParseTuple(args, "O", &max)) {
	68	PyErr_SetString(PyExc_TypeError, "could not parse arguments");
	69	return NULL;
	70	}
	71
	72	// create the storage number
	73	mpz_t a, b;
	74	mpz_init(a);
	75	mpz_init(b);
	76
	77	// cast it to an mpz
	78	pynum_to_mpz(max, a);
	79
	80	// get a value
	81	pbc_mpz_random(b, a);
	82
	83	// cast it back to a pylong
	84	PyObject *lng = mpz_to_pynum(b);
	85
	86	// clean up
	87	mpz_clear(a);
	88	mpz_clear(b);
	89
	90	// return it
	91	return lng;
	92	}
71	93
72	94	/*******************************************************************************
73	95	* Params *
…	…
1064	1064
1065	1065	PyMethodDef pypbc_methods[] = {
1066	1066	{"get_random_prime", get_random_prime, METH_VARARGS, "get a random n-bit prime"},
	1067	{"get_random", get_random, METH_VARARGS, "get a random value less than n"},
1067	1068	{NULL, NULL, 0, NULL}
1068	1069	};
1069	1070

Commit a462f537af43fe136e28a5a75a7128697904b4ef

Gitorious