def _finish_greater_than_equal(self, results, l):
"""Finish the calculation."""
T = results[0]
bit_bits = results[1:]
vec = [(GF256(0), GF256(0))]
# Calculate the vector, using only the first l bits
for i, bi in enumerate(bit_bits[:l]):
Ti = GF256(T.bit(i))
ci = Share(self, GF256, bi ^ Ti)
vec.append((ci, Ti))
# Reduce using the diamond operator. We want to do as much
# as possible in parallel while being careful not to
# switch the order of elements since the diamond operator
# is non-commutative.
while len(vec) > 1:
tmp = []
while len(vec) > 1:
tmp.append(self._diamond(vec.pop(0), vec.pop(0)))
if len(vec) == 1:
tmp.append(vec[0])
vec = tmp
return GF256(T.bit(l)) ^ (bit_bits[l] ^ vec[0][1])
def test_prss_share_random_bit(self, runtime):
"""Tests the sharing of a 0/1 GF256 element using PRSS."""
a = runtime.prss_share_random(field=GF256, binary=True)
self.assert_type(a, Share)
opened_a = runtime.open(a)
opened_a.addCallback(self.assertIn, [GF256(0), GF256(1)])
return opened_a
def test_add(self):
"""Test addition."""
self._test_binary_operator(operator.add, 0, 0, 0)
self._test_binary_operator(operator.add, 1, 1, 0)
self._test_binary_operator(operator.add, 100, 100, 0)
self._test_binary_operator(operator.add, 0, 1, 1)
self._test_binary_operator(operator.add, 1, 2, 3)
a = GF256(10)
a += GF256(10)
self.assertEquals(a, GF256(0))
def test_prss_share_random_multi_bit(self, runtime):
"""Tests the sharing of several 0/1 GF256 elements using PRSS."""
a_list = runtime.prss_share_random_multi(field=GF256,
quantity=8,
binary=True)
for a in a_list:
self.assert_type(a, Share)
opened_a = runtime.open(a)
opened_a.addCallback(self.assertIn, [GF256(0), GF256(1)])
return gather_shares(a_list)
def key_expansion(self, key, new_length=None):
"""Rijndael key expansion.
Input and output are lists of 4-byte columns (words).
*new_length* is the round for which the key should be expanded.
If ommitted, the key is expanded for all rounds."""
assert len(key) >= self.n_k, "Wrong key size."
assert len(key[0]) == 4, "Key must consist of 4-byte words."
expanded_key = key
if new_length == None:
new_length = self.rounds
for i in xrange(len(key), self.n_b * (new_length + 1)):
temp = list(expanded_key[i - 1])
if i % self.n_k == 0:
temp.append(temp.pop(0))
self.byte_sub([temp])
temp[0] += GF256(2) ** (i / self.n_k - 1)
elif self.n_k > 6 and i % self.n_k == 4:
self.byte_sub([temp])
new_word = []
for j in xrange(4):
new_word.append(expanded_key[i - self.n_k][j] + temp[j])
expanded_key.append(new_word)
return expanded_key
def protocol(rt):
l = 7
rand = dict([(i, random.Random(i)) for i in players])
inputs = []
for i in range(count):
input = dict([(j, rand[j].randint(0, pow(2, l))) for j in players])
inputs.append(input)
# Fixed input for easier debugging
inputs.append({1: 20, 2: 25, 3: 0})
print "I am player %d, will compare %d numbers" % (id, len(inputs))
bits = []
for input in inputs:
x, y, z = rt.shamir_share([1, 2, 3], Zp, input[id])
bit = rt.open(x >= y)
bit.addCallback(lambda b: b == GF256(1))
bit.addCallback(lambda b, x, y: "%3d >= %3d: %-5s (%s)" \
% (x, y, b, b == (x >= y)), input[1], input[2])
dprint("%s", bit)
bits.append(bit)
results = gatherResults(bits)
results.addCallback(lambda _: rt.shutdown())
def test_key_expansion(self, runtime):
aes = AES(runtime, 256, quiet=True)
key = []
ascii_key = []
for i in xrange(8):
key.append([])
for j in xrange(4):
b = 15 * i + j
key[i].append(Share(runtime, GF256, GF256(b)))
ascii_key.append(chr(b))
result = aes.key_expansion(key)
r = rijndael(ascii_key)
expected_result = []
for round_key in r.Ke:
for word in round_key:
split_word = []
expected_result.append(split_word)
for j in xrange(4):
split_word.insert(0, word % 256)
word /= 256
self.verify(runtime, result, expected_result)
def test_prss_share_zero_bit(self, runtime):
"""Tests the sharing of a zero GF256 element using PRSS."""
a = runtime.prss_share_zero(GF256, 1)[0]
self.assert_type(a, Share)
opened_a = runtime.open(a, threshold=2 * runtime.threshold)
opened_a.addCallback(self.assertEquals, GF256(0))
return opened_a
def preprocess(self, input):
if isinstance(input, str):
return [Share(self.runtime, GF256, GF256(ord(c))) for c in input]
else:
for byte in input:
assert byte.field == GF256, \
"Input must be a list of GF256 elements " \
"or of shares thereof."
return input
def _test_binary_operator(self, operation, a, b, expected):
"""Test C{operation} with and without coerced operands."""
result = operation(GF256(a), GF256(b))
self.assertEquals(result, GF256(expected))
result = operation(GF256(a), b)
self.assertEquals(result, GF256(expected))
result = operation(a, GF256(b))
self.assertEquals(result, GF256(expected))
def protocol(rt):
print "Starting protocol"
Zp = GF(11)
a, b, c = rt.prss_share([1, 2, 3], Zp, 0)
x, y, z = rt.prss_share([1, 2, 3], Zp, 1)
a_b = rt.open(rt.convert_bit_share(a, GF256))
b_b = rt.open(rt.convert_bit_share(b, GF256))
c_b = rt.open(rt.convert_bit_share(c, GF256))
x_b = rt.open(rt.convert_bit_share(x, GF256))
y_b = rt.open(rt.convert_bit_share(y, GF256))
z_b = rt.open(rt.convert_bit_share(z, GF256))
def check(result, variable, expected):
if result == expected:
print "%s: %s (correct)" % (variable, result)
else:
print "%s: %s (incorrect, expected %d)" \
% (variable, result, expected)
a_b.addCallback(check, "a_b", GF256(0))
b_b.addCallback(check, "b_b", GF256(0))
c_b.addCallback(check, "c_b", GF256(0))
x_b.addCallback(check, "x_b", GF256(1))
y_b.addCallback(check, "y_b", GF256(1))
z_b.addCallback(check, "z_b", GF256(1))
rt.wait_for(a_b, b_b, c_b, x_b, y_b, z_b)
def test_convert_bit_share(self, runtime):
"""Test conversion 0/1 element conversion from Zp to GF256."""
# TODO: test conversion from GF256 to Zp and between Zp and Zq
# fields.
results = []
for value in 0, 1:
share = Share(runtime, self.Zp, self.Zp(value))
converted = runtime.convert_bit_share(share, GF256)
self.assertEquals(converted.field, GF256)
opened = runtime.open(converted)
opened.addCallback(self.assertEquals, GF256(value))
results.append(opened)
return gatherResults(results)
def synchronize(self):
"""Introduce a synchronization point.
Returns a :class:`Deferred` which will trigger if and when all
other players have made their calls to :meth:`synchronize`. By
adding callbacks to the returned :class:`Deferred`, one can
divide a protocol execution into disjoint phases.
"""
self.increment_pc()
shares = [self._exchange_shares(player, GF256(0))
for player in self.players]
result = gather_shares(shares)
result.addCallback(lambda _: None)
return result
def _test_byte_sub(self, runtime, aes):
results = []
expected_results = []
for i in range(4):
results.append([])
expected_results.append([])
for j in range(4):
b = 60 * i + j
results[i].append(Share(runtime, GF256, GF256(b)))
expected_results[i].append(S[b])
aes.byte_sub(results)
self.verify(runtime, results, expected_results)
def invert(rt):
aes = AES(rt, 192, use_exponentiation=options.exponentiation)
bytes = [
Share(rt, GF256, GF256(random.randint(0, 255)))
for i in range(options.count)
]
start = time.time()
done = gather_shares([aes.invert(byte) for byte in bytes])
def finish(_):
duration = time.time() - start
print "Finished after %.3f s." % duration
print "Time per inversion: %.3f ms" % (1000 * duration / options.count)
rt.shutdown()
done.addCallback(finish)
def prss_share_bit_double(self, field):
"""Share a random bit over *field* and GF256.
The protocol is described in "Efficient Conversion of
Secret-shared Values Between Different Fields" by Ivan Damgård
and Rune Thorbek available as `Cryptology ePrint Archive,
Report 2008/221 <http://eprint.iacr.org/2008/221>`__.
"""
n = self.num_players
k = self.options.security_parameter
prfs = self.players[self.id].prfs(2**k)
prss_key = self.prss_key()
b_p = self.prss_share_random(field, binary=True)
r_p, r_lsb = prss_lsb(n, self.id, field, prfs, prss_key)
b = self.open(b_p + r_p)
# Extract least significant bit and change field to GF256.
b.addCallback(lambda i: GF256(i.value & 1))
b.field = GF256
# Use r_lsb to flip b as needed.
return (b_p, b ^ r_lsb)
def prss_shamir_share_bit_double(self, field):
"""Shamir share a random bit over *field* and GF256."""
n = self.num_players
k = self.options.security_parameter
prfs = self.players[self.id].prfs(2**k)
prss_key = self.prss_key()
inputters = range(1, self.num_players + 1)
ri = rand.randint(0, 2**k - 1)
ri_p = self.shamir_share(inputters, field, ri)
ri_lsb = self.shamir_share(inputters, GF256, ri & 1)
r_p = reduce(self.add, ri_p)
r_lsb = reduce(self.add, ri_lsb)
b_p = self.prss_share_random(field, binary=True)
b = self.open(b_p + r_p)
# Extract least significant bit and change field to GF256.
b.addCallback(lambda i: GF256(i.value & 1))
b.field = GF256
# Use r_lsb to flip b as needed.
return (b_p, b ^ r_lsb)
def decompose(byte, bits):
value = byte.value
for i in range(8):
c_bits[i].callback(GF256(value & 1))
value >>= 1
def test_prss_lsb(self):
(share, bit) = prss.prss_lsb(None, None, self.field, None, None)
self.assertEquals(share, self.field(7))
self.assertEquals(bit, GF256(1))
def test_neg(self):
"""Test negation."""
self.assertEquals(-GF256(0), GF256(0))
self.assertEquals(-GF256(10), GF256(10))
self.assertEquals(-GF256(100), GF256(100))
def test_str(self):
"""Test string conversion."""
self.assertEquals(str(GF256(0)), "[0]")
self.assertEquals(str(GF256(1)), "[1]")
self.assertEquals(str(GF256(10)), "[10]")
def test_bit_decomposition(self, runtime):
share = Share(runtime, GF256, GF256(99))
return self.verify(runtime, bit_decompose(share),
[1, 1, 0, 0, 0, 1, 1, 0])
def check_outputs(outputs):
for o in outputs:
self.assertIn("opened a: %s" % GF256(17), o)
self.assertIn("opened b: %s" % GF256(40), o)
self.assertIn("opened c: %s" % GF256(235), o)
return convert_replicated_shamir(n, j, field, rep_shares)
def prss_multi(n, j, field, prfs, key, modulus, quantity):
"""Does the same as :meth:`prss`, but multiple times in order to
call the PRFs less frequently.
"""
prf_results = random_replicated_sharing(j, prfs, key)
rep_shares_list = [[] for i in range(quantity)]
for subset, result in prf_results:
for i in range(quantity):
rep_shares_list[i].append((subset, result % modulus))
result /= modulus
return [convert_replicated_shamir(n, j, field, rep_shares)
for rep_shares in rep_shares_list]
@fake(lambda n, j, field, prfs, key: (field(7), GF256(1)))
def prss_lsb(n, j, field, prfs, key):
"""Share a pseudo-random number and its least significant bit.
The random number is shared over *field* and its least significant
bit is shared over :class:`viff.field.GF256`. It is important the
*prfs* generate numbers much less than the size of *field* -- we
must be able to do an addition for each PRF without overflow in
*field*.
>>> from field import GF
>>> Zp = GF(23)
>>> prfs = {frozenset([1,2]): PRF("a", 7),
... frozenset([1,3]): PRF("b", 7),
... frozenset([2,3]): PRF("c", 7)}
>>> prss_lsb(3, 1, Zp, prfs, "key")
def test_construct(self):
"""Test overflows in constructor."""
self.assertEquals(GF256(256), GF256(0))
self.assertEquals(GF256(257), GF256(1))
def test_invert(self):
"""Test inverse operation, including inverting zero."""
self.assertRaises(ZeroDivisionError, lambda: ~GF256(0))
self.assertEquals(~GF256(1), GF256(1))
def test_field(self):
"""Test field attribute."""
self.assertIdentical(GF256.field, GF256)
self.assertIdentical(GF256(10).field, GF256)
def test_div(self):
"""Test division, including division by zero."""
self.assertRaises(ZeroDivisionError, lambda: GF256(10) / GF256(0))
self.assertEquals(GF256(10) / GF256(10), GF256(1))
self.assertEquals(GF256(10) / GF256(9), GF256(208))
self.assertEquals(GF256(10) / GF256(5), GF256(2))
self.assertEquals(10 / GF256(5), GF256(2))
class AES:
"""AES instantiation.
This class is used together with a :class:`~viff.runtime.Runtime`
object::
aes = AES(runtime, 192)
cleartext = [Share(runtime, GF256, GF256(0)) for i in range(128/8)]
key = [runtime.prss_share_random(GF256) for i in range(192/8)]
ciphertext = aes.encrypt("abcdefghijklmnop", key)
ciphertext = aes.encrypt(cleartext, "keykeykeykeykeykeykeykey")
ciphertext = aes.encrypt(cleartext, key)
In every case *ciphertext* will be a list of shares over GF256.
"""
def __init__(self, runtime, key_size, block_size=128,
use_exponentiation=False, quiet=False):
"""Initialize Rijndael.
AES(runtime, key_size, block_size), whereas key size and block
size must be given in bits. Block size defaults to 128."""
assert key_size in [128, 192, 256], \
"Key size must be 128, 192 or 256"
assert block_size in [128, 192, 256], \
"Block size be 128, 192 or 256"
self.n_k = key_size / 32
self.n_b = block_size / 32
self.rounds = max(self.n_k, self.n_b) + 6
self.runtime = runtime
if use_exponentiation is not False:
if (isinstance(use_exponentiation, int) and
use_exponentiation < len(AES.exponentiation_variants)):
use_exponentiation = \
AES.exponentiation_variants[use_exponentiation]
elif use_exponentiation not in AES.exponentation_variants:
use_exponentiation = "shortest_sequential_chain"
if not quiet:
print "Use %s for inversion by exponentiation." % \
use_exponentiation
if use_exponentiation == "standard_square_and_multiply":
self.invert = lambda byte: byte ** 254
elif use_exponentiation == "shortest_chain_with_least_rounds":
self.invert = self.invert_by_exponentiation_with_less_rounds
elif use_exponentiation == "chain_with_least_rounds":
self.invert = self.invert_by_exponentiation_with_least_rounds
elif use_exponentiation == "masked":
self.invert = self.invert_by_masked_exponentiation
elif use_exponentiation == "masked_online":
self.invert = self.invert_by_masked_exponentiation_online
else:
self.invert = self.invert_by_exponentiation
else:
self.invert = self.invert_by_masking
if not quiet:
print "Use inversion by masking."
exponentiation_variants = ["standard_square_and_multiply",
"shortest_sequential_chain",
"shortest_chain_with_least_rounds",
"chain_with_least_rounds",
"masked",
"masked_online"]
def invert_by_masking(self, byte):
bits = bit_decompose(byte)
for j in range(len(bits)):
bits[j].addCallback(lambda x: 1 - x)
# bits[j] = 1 - bits[j]
while len(bits) > 1:
bits.append(bits.pop(0) * bits.pop(0))
# b == 1 if byte is 0, b == 0 else
b = bits[0]
r = Share(self.runtime, GF256)
c = Share(self.runtime, GF256)
def get_masked_byte(c_opened, r_related, c, r, byte):
if c_opened == 0:
r_trial = self.runtime.prss_share_random(GF256)
c_trial = self.runtime.open((byte + b) * r_trial)
self.runtime.schedule_callback(c_trial, get_masked_byte,
r_trial, c, r, byte)
else:
r_related.addCallback(r.callback)
c.callback(~c_opened)
get_masked_byte(0, None, c, r, byte)
# necessary to avoid communication in multiplication
# was: return c * r - b
result = gather_shares([c, r, b])
result.addCallback(lambda (c, r, b): c * r - b)
return result
def invert_by_masked_exponentiation(self, byte):
def add_and_multiply(masked_byte, random_powers, prep):
masked_powers = self.runtime.powerchain(masked_byte, 7)
byte_powers = map(operator.add, masked_powers, random_powers)[1:]
if prep:
byte_powers = [Share(self.runtime, GF256, value)
for value in byte_powers]
while len(byte_powers) > 1:
byte_powers.append(byte_powers.pop(0) * byte_powers.pop(0))
return byte_powers[0]
random_powers, prep = self.runtime.prss_powerchain()
masked_byte = self.runtime.open(byte + random_powers[0])
return self.runtime.schedule_callback(
masked_byte, add_and_multiply, random_powers, prep)
# constants for efficient computation of x^2, x^4, x^8 etc.
powers_of_two = [[GF256(2**j)**(2**i) for j in range(8)] for i in range(8)]
def invert_by_masked_exponentiation_online(self, byte):
bits = bit_decompose(byte)
byte_powers = []
for i in range(1,8):
byte_powers.append(self.runtime.lin_comb(AES.powers_of_two[i], bits))
while len(byte_powers) > 1:
byte_powers.append(byte_powers.pop(0) * byte_powers.pop(0))
return byte_powers[0]
def invert_by_exponentiation(self, byte):
byte_2 = byte * byte
byte_3 = byte_2 * byte
byte_6 = byte_3 * byte_3
byte_12 = byte_6 * byte_6
byte_15 = byte_12 * byte_3
byte_30 = byte_15 * byte_15
byte_60 = byte_30 * byte_30
byte_63 = byte_60 * byte_3
byte_126 = byte_63 * byte_63
byte_252 = byte_126 * byte_126
byte_254 = byte_252 * byte_2
return byte_254
def invert_by_exponentiation_with_less_rounds(self, byte):
byte_2 = byte * byte
byte_4 = byte_2 * byte_2
byte_8 = byte_4 * byte_4
byte_9 = byte_8 * byte
byte_18 = byte_9 * byte_9
byte_19 = byte_18 * byte
byte_36 = byte_18 * byte_18
byte_55 = byte_36 * byte_19
byte_72 = byte_36 * byte_36
byte_127 = byte_72 * byte_55
byte_254 = byte_127 * byte_127
return byte_254
def invert_by_exponentiation_with_least_rounds(self, byte):
byte_2 = byte * byte
byte_3 = byte_2 * byte
byte_4 = byte_2 * byte_2
byte_7 = byte_4 * byte_3
byte_8 = byte_4 * byte_4
byte_15 = byte_8 * byte_7
byte_16 = byte_8 * byte_8
byte_31 = byte_16 * byte_15
byte_32 = byte_16 * byte_16
byte_63 = byte_32 * byte_31
byte_64 = byte_32 * byte_32
byte_127 = byte_64 * byte_63
byte_254 = byte_127 * byte_127
return byte_254
# matrix for byte_sub, the last column is the translation vector
A = Matrix([[1,0,0,0,1,1,1,1],
[1,1,0,0,0,1,1,1],
[1,1,1,0,0,0,1,1],
[1,1,1,1,0,0,0,1],
[1,1,1,1,1,0,0,0],
[0,1,1,1,1,1,0,0],
[0,0,1,1,1,1,1,0],
[0,0,0,1,1,1,1,1]])
# anticipate bit recombination
for i, row in enumerate(A.rows):
for j in range(len(row)):
row[j] *= 2 ** i
def byte_sub(self, state, use_lin_comb=True):
"""ByteSub operation of Rijndael.
The first argument should be a matrix consisting of elements
of GF(2^8)."""
for h in range(len(state)):
row = state[h]
for i in range(len(row)):
bits = bit_decompose(self.invert(row[i]))
if use_lin_comb:
row[i] = self.runtime.lin_comb(sum(AES.A.rows, []),
bits * len(AES.A.rows))
else:
# caution: order is lsb first
vector = AES.A * Matrix(zip(bits))
bits = zip(*vector.rows)[0]
row[i] = sum(bits)
row[i].addCallback(lambda x: 0x63 + x)
def shift_row(self, state):
"""Rijndael ShiftRow.
State should be a list of 4 rows."""
assert len(state) == 4, "Wrong state size."
if self.n_b in [4,6]:
offsets = [0, 1, 2, 3]
else:
offsets = [0, 1, 3, 4]
for i, row in enumerate(state):
for j in range(offsets[i]):
row.append(row.pop(0))
# matrix for mix_column
C = [[2, 3, 1, 1],
[1, 2, 3, 1],
[1, 1, 2, 3],
[3, 1, 1, 2]]
C = Matrix(C)
def mix_column(self, state, use_lin_comb=True):
"""Rijndael MixColumn.
Input should be a list of 4 rows."""
assert len(state) == 4, "Wrong state size."
if use_lin_comb:
columns = zip(*state)
for i, row in enumerate(state):
row[:] = [self.runtime.lin_comb(AES.C.rows[i], column)
for column in columns]
else:
state[:] = (AES.C * Matrix(state)).rows
def add_round_key(self, state, round_key):
"""Rijndael AddRoundKey.
State should be a list of 4 rows and round_key a list of
4-byte columns (words)."""
assert len(round_key) == self.n_b, "Wrong key size."
assert len(round_key[0]) == 4, "Key must consist of 4-byte words."
state[:] = (Matrix(state) + Matrix(zip(*round_key))).rows
def key_expansion(self, key, new_length=None):
"""Rijndael key expansion.
Input and output are lists of 4-byte columns (words).
*new_length* is the round for which the key should be expanded.
If ommitted, the key is expanded for all rounds."""
assert len(key) >= self.n_k, "Wrong key size."
assert len(key[0]) == 4, "Key must consist of 4-byte words."
expanded_key = key
if new_length == None:
new_length = self.rounds
for i in xrange(len(key), self.n_b * (new_length + 1)):
temp = list(expanded_key[i - 1])
if i % self.n_k == 0:
temp.append(temp.pop(0))
self.byte_sub([temp])
temp[0] += GF256(2) ** (i / self.n_k - 1)
elif self.n_k > 6 and i % self.n_k == 4:
self.byte_sub([temp])
new_word = []
for j in xrange(4):
new_word.append(expanded_key[i - self.n_k][j] + temp[j])
expanded_key.append(new_word)
return expanded_key
def preprocess(self, input):
if isinstance(input, str):
return [Share(self.runtime, GF256, GF256(ord(c)))
for c in input]
else:
for byte in input:
assert byte.field == GF256, \
"Input must be a list of GF256 elements " \
"or of shares thereof."
return input
def encrypt(self, cleartext, key, benchmark=False, prepare_at_once=False):
"""Rijndael encryption.
Cleartext and key should be either a string or a list of bytes
(possibly shared as elements of GF256)."""
start = time.time()
self.runtime.increment_pc()
self.runtime.fork_pc()
assert len(cleartext) == 4 * self.n_b, "Wrong length of cleartext."
assert len(key) == 4 * self.n_k, "Wrong length of key."
cleartext = self.preprocess(cleartext)
key = self.preprocess(key)
state = [cleartext[i::4] for i in xrange(4)]
key = [key[4*i:4*i+4] for i in xrange(self.n_k)]
if benchmark:
global preparation, communication
preparation = 0
communication = 0
def progress(x, i, start_round):
time_diff = time.time() - start_round
global communication
communication += time_diff
print "Round %2d: %f, %f" % \
(i, time_diff, time.time() - start)
return x
def prep_progress(i, start_round):
time_diff = time.time() - start_round
global preparation
preparation += time_diff
print "Round %2d preparation: %f, %f" % \
(i, time_diff, time.time() - start)
else:
progress = lambda x, i, start_round: x
prep_progress = lambda i, start_round: None
expanded_key = self.key_expansion(key[:], 0)
self.add_round_key(state, expanded_key[0:self.n_b])
prep_progress(0, start)
def get_trigger(state):
return gather_shares(reduce(operator.add, state))
def round(_, state, i):
start_round = time.time()
self.key_expansion(expanded_key, i)
self.byte_sub(state)
self.shift_row(state)
self.mix_column(state)
self.add_round_key(state, expanded_key[i*self.n_b:(i+1)*self.n_b])
if not prepare_at_once:
trigger = get_trigger(state)
trigger.addCallback(progress, i, time.time())
if i < self.rounds - 1:
self.runtime.schedule_complex_callback(trigger, round, state, i + 1)
else:
self.runtime.schedule_complex_callback(trigger, final_round, state)
prep_progress(i, start_round)
return _
def final_round(_, state):
start_round = time.time()
self.key_expansion(expanded_key, self.rounds)
self.byte_sub(state)
self.shift_row(state)
self.add_round_key(state, expanded_key[self.rounds*self.n_b:])
trigger = get_trigger(state)
trigger.addCallback(progress, self.rounds, time.time())
if benchmark:
trigger.addCallback(finish, state)
# connect to final result
for a, b in zip(reduce(operator.add, zip(*state)), result):
a.addCallback(b.callback)
prep_progress(self.rounds, start_round)
return _
def finish(_, state):
print "Total preparation time: %f" % preparation
print "Total communication time: %f" % communication
return _
result = [Share(self.runtime, GF256) for i in xrange(4 * self.n_b)]
if prepare_at_once:
for i in range(1, self.rounds):
round(None, state, i)
final_round(None, state)
else:
round(None, state, 1)
self.runtime.unfork_pc()
return result
def test_pow(self):
"""Test exponentiation."""
self.assertEquals(GF256(3)**3, GF256(3) * GF256(3) * GF256(3))
self.assertEquals(GF256(27)**100, GF256(27)**50 * GF256(27)**50)
