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_secretsharing(self):
for field in (self.f2, self.f256):
t = 0
m = 1
a = [field(0), field(1)]
shares = thresha.random_split(a, t, m)
b = thresha.recombine(field, [(j + 1, shares[j]) for j in range(len(shares))])
self.assertEqual(a, b)
b = thresha.recombine(field, [(j + 1, shares[j]) for j in range(len(shares))], [0])[0]
self.assertEqual(a, b)
for field in (self.f19, self.f27, self.f256):
for t in range(8):
m = 2 * t + 1
for i in range(t):
a = [field(i), field(i+1), field(i**2), field((i+1)**2)]
shares = thresha.random_split(a, t, m)
b = thresha.recombine(field, [(j + 1, shares[j]) for j in range(len(shares))])
self.assertEqual(a, b)
m = 17
for t in range((m + 1) // 2):
for i in range(t):
a = [field(i), field(i+1), field(i**2), field((i+1)**2)]
shares = thresha.random_split(a, t, m)
b = thresha.recombine(field, [(j + 1, shares[j]) for j in range(len(shares))])
self.assertEqual(a, b)
def test_secretsharing(self):
field = self.f2
t = 0
n = 1
a = [field(0), field(1)]
shares = thresha.random_split(a, t, n)
b = thresha.recombine(field,
[(j + 1, shares[j]) for j in range(len(shares))])
self.assertEqual(a, b)
field = self.f19
for t in range(8):
n = 2 * t + 1
for i in range(t):
a = [field(i), field(-i), field(i**2), field(-i**2)]
shares = thresha.random_split(a, t, n)
b = thresha.recombine(field, [(j + 1, shares[j])
for j in range(len(shares))])
self.assertEqual(a, b)
n = 17
for t in range((n + 1) // 2):
for i in range(t):
a = [field(i), field(-i), field(i**2), field(-i**2)]
shares = thresha.random_split(a, t, n)
b = thresha.recombine(field, [(j + 1, shares[j])
for j in range(len(shares))])
self.assertEqual(a, b)
async def _reshare(self, x):
x_is_list = isinstance(x, list)
if not x_is_list:
x = [x]
sftype = type(x[0]) # all elts assumed of same type
if issubclass(sftype, Share):
field = sftype.field
if not field.frac_length:
await returnType(sftype, len(x))
else:
await returnType((sftype, x[0].integral), len(x))
x = await gather_shares(x)
else:
field = sftype
await returnType(Future)
m = len(self.parties)
t = self.threshold
in_shares = thresha.random_split(x, t, m)
in_shares = [field.to_bytes(elts) for elts in in_shares]
# Recombine the first 2t+1 output_shares.
out_shares = await gather_shares(self._exchange_shares(in_shares)[:2 * t + 1])
points = [(j + 1, field.from_bytes(out_shares[j])) for j in range(len(out_shares))]
y = thresha.recombine(field, points)
if issubclass(sftype, Share):
y = [sftype(s) for s in y]
if not x_is_list:
y = y[0]
return y
async def _recombine(self, x, receivers, t):
"""Recombine shares of elements of x."""
sftype = type(x[0]) # all elts assumed of same type
if issubclass(sftype, Share):
field = sftype.field
if not field.frac_length:
await returnType(sftype, len(x))
else:
await returnType((sftype, x[0].integral), len(x))
x = await gather_shares(x)
else:
field = sftype
await returnType(Future, len(x))
m = len(self.parties)
x = [a.value for a in x]
# Send share to all successors in receivers.
for peer_pid in receivers:
if 0 < (peer_pid - self.pid) % m <= t:
self._send_shares(peer_pid, field.to_bytes(x))
# Receive and recombine shares if this party is a receiver.
if self.pid in receivers:
shares = [None] * t
for i in range(t):
shares[i] = self._receive_shares((self.pid - t + i) % m)
shares = await gather_shares(shares)
points = [((self.pid - t + j) % m + 1, field.from_bytes(shares[j])) for j in range(t)]
points.append((self.pid + 1, x))
return thresha.recombine(field, points)
return [None] * len(x)
async def _reshare(self, a):
if not isinstance(a, list):
a = tuple([a])
sftype = type(a[0]) # all elts assumed of same type
if issubclass(sftype, Share):
if sftype.field.frac_length == 0:
await returnType(sftype, len(a))
else:
await returnType((sftype, a[0].integral), len(a))
a = await mpc.gather(a)
field = sftype.field
else:
await returnType(Share)
field = sftype
in_shares = thresha.random_split(a, self.threshold, len(self.parties))
in_shares = [field.to_bytes(elts) for elts in in_shares]
# Recombine the first 2t+1 output_shares.
out_shares = await gather_shares(
self._exchange_shares(in_shares)[:2 * self.threshold + 1])
b = thresha.recombine(field, [(j + 1, field.from_bytes(out_shares[j]))
for j in range(len(out_shares))])
if issubclass(sftype, Share):
b = [sftype(s) for s in b]
if isinstance(a, tuple):
return b[0]
else:
return b
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)
async def _recombine(self, a, receivers=None, threshold=None):
"""Recombine shares of a.
The receivers are the parties that will obtain the result.
The default is to let everybody know the result.
"""
# all parties receive result by default
if receivers is None:
receivers = list(range(len(self.parties)))
if threshold is None:
threshold = self.threshold
if not isinstance(a, list):
a = tuple([a])
sftype = type(a[0]) # all elts assumed of same type
if issubclass(sftype, Share):
if sftype.field.frac_length == 0:
await returnType(sftype)
else:
await returnType((sftype, a[0].integral))
a = await gather_shares(a)
field = type(a[0])
else:
await returnType(Share)
field = sftype
# Send share to all successors in receivers.
for peer_id in receivers:
if 0 < (peer_id - self.id) % len(self.parties) <= threshold:
self._send_share(peer_id, field.to_bytes(list(a)))
# Receive and recombine shares if this party is a receiver.
if self.id in receivers:
shares = [None] * threshold
for i in range(threshold):
shares[i] = self._expect_share(
(self.id - threshold + i) % len(self.parties))
shares = await gather_shares(shares)
shares = [((self.id - threshold + j) % len(self.parties) + 1,
field.from_bytes(shares[j])) for j in range(threshold)]
shares.append((self.id + 1, list(a)))
b = thresha.recombine(field, shares)
if isinstance(a, tuple):
return b[0]
else:
return b
else:
return