def test_prf(self):
key = int('0x00112233445566778899aabbccddeeff', 16).to_bytes(16, byteorder='little')
bound = 1
F = thresha.PRF(key, bound)
y = F('test')
self.assertEqual(y, 0)
bound = 100
F = thresha.PRF(key, bound)
x = ''
y = F(x.encode())
self.assertTrue(0 <= y < bound)
y2 = F(x.encode())
self.assertEqual(y, y2)
def test_prss(self):
field = self.f256
key = int('0x00112233445566778899aabbccddeeff',
16).to_bytes(16, byteorder='little')
bound = 256 # field.modulus
F = thresha.PRF(key, bound)
m = 1
pid = 0
prfs = {(0, ): F}
uci = 'test uci'.encode()
n = 8
a = F(uci, n)
shares = thresha.pseudorandom_share(field, m, pid, prfs, uci, n)
b = thresha.recombine(field, [(1, shares)])
self.assertEqual(a, [s.value for s in b])
a = [0] * n
shares = thresha.pseudorandom_share_zero(field, m, pid, prfs, uci, n)
b = thresha.recombine(field, [(1, shares)])
self.assertEqual(a, b)
m = 3
pid = 0
prfs = {(0, 1): F, (0, 2): F} # reuse dummy PRF
shares0 = thresha.pseudorandom_share_zero(field, m, pid, prfs, uci, n)
pid = 1
prfs = {(0, 1): F, (1, 2): F} # reuse dummy PRF
shares1 = thresha.pseudorandom_share_zero(field, m, pid, prfs, uci, n)
pid = 2
prfs = {(0, 2): F, (1, 2): F} # reuse dummy PRF
shares2 = thresha.pseudorandom_share_zero(field, m, pid, prfs, uci, n)
b = thresha.recombine(field, [(1, shares0), (2, shares1),
(3, shares2)])
self.assertEqual(a, b)
def test_prf(self):
key = b'00112233445566778899aabbccddeeff'
max = 100
F = thresha.PRF(key, max)
x = ''
y = F(x)
self.assertTrue(0 <= y < max)
y2 = F(x)
self.assertEqual(y, y2)
def prfs(self, bound):
"""PRFs with codomain range(bound) for pseudorandom secret sharing.
Return a mapping from sets of parties to PRFs.
"""
f = {}
for subset, key in self._prss_keys.items():
if len(subset) == len(self.parties) - self.threshold:
f[subset] = thresha.PRF(key, bound)
return f
def prfs(self, bound):
"""PRFs with codomain range(bound) for pseudorandom secret sharing.
Return a mapping from sets of parties to PRFs.
"""
try:
return self._prfs[bound]
except KeyError:
self._prfs[bound] = {}
for subset, key in self.keys.items():
self._prfs[bound][subset] = thresha.PRF(key, bound)
return self._prfs[bound]
def test_prss(self):
field = self.f19
key = b'00112233445566778899aabbccddeeff'
max = field.modulus
F = thresha.PRF(key, max)
n = 1
id = 0
prfs = {frozenset([0]): F}
uci = 'test uci'
m = 8
a = F(uci, m)
shares = thresha.pseudorandom_share(field, n, id, prfs, uci, m)
b = thresha.recombine(field, [(1, shares)])
self.assertEqual(a, b)
a = [0] * m
shares = thresha.pseudorandom_share_zero(field, n, id, prfs, uci, m)
b = thresha.recombine(field, [(1, shares)])
self.assertEqual(a, b)