def A_2(fn):
output1 = fn("\x00" * block_len)
y1, y2 = split(output1)
output2 = fn(y1)
y3, y4 = split(output2)
if (y2 == y3):
return 1 #I think I'm in Real
else:
return 0 #I think I'm in Rand
pass
from crypto.games.game_prf import GamePRF
from crypto.simulator.world_sim import WorldSim
if __name__ == '__main__':
g_1 = GamePRF(G1, key_len, block_len, 2 * block_len)
s_1 = WorldSim(g_1, A_1)
g_2 = GamePRF(G2, key_len, block_len, 2 * block_len)
s_2 = WorldSim(g_2, A_2)
print "The advantage of your adversary A_1 is ~" + \
str(s_1.compute_advantage())
print "The advantage of your adversary A_2 is ~" + \
str(s_2.compute_advantage())
"""
for all 128-bit strings k, x. Show that F is not a secure PRF by presenting
a practical adversary A such that Adv(prf, F, A) is close to one. Fill in the
code for adversary A, verify it's advantage by running your code and describe
the running time.
"""
def A(fn):
"""
You must fill in this method. This is the adversary that the problem is
asking for.
:param fn: This is the oracle supplied by GamePRF, you can call this
oracle to get an "encryption" of the data you pass into it.
:return: return 1 to indicate your adversary believes it is the real world
and return 0 to indicate that your adversary believes it is in the random
world.
"""
return None
from crypto.games.game_prf import GamePRF
from crypto.simulator.world_sim import WorldSim
if __name__ == '__main__':
g = GamePRF(F, 16, 32)
s = WorldSim(g, A)
print "The advantage of your adversary is ~" + str(s.compute_advantage())
def A_2(fn):
"""
You must fill in this method.
:param fn: This is the oracle supplied by GamePRF, you can call this
oracle to get an "encryption" of the data you pass into it.
:return: return 1 to indicate your adversary believes it is the real world
and return 0 to indicate that your adversary believes it is in the random
world.
"""
pass
from crypto.games.game_prf import GamePRF
from crypto.simulator.world_sim import WorldSim
if __name__ == '__main__':
g_1 = GamePRF(G(1), key_len, 2*block_len)
s_1 = WorldSim(g_1, A_1)
g_2 = GamePRF(G(2), key_len, 2*block_len)
s_2 = WorldSim(g_2, A_2)
print "The advantage of your adversary A_1 is ~" + \
str(s_1.compute_advantage())
print "The advantage of your adversary A_2 is ~" + \
str(s_2.compute_advantage())
oracle. Fill in the code for adversary A, verify it's advantage by running your code and describe the running time.
"""
def A(fn):
"""
You must fill in this method.
:param fn: This is the oracle supplied by GamePRF, you can call this
oracle to get an "encryption" of the data you pass into it.
:return: return 1 to indicate your adversary believes it is the real world
and return 0 to indicate that your adversary believes it is in the random
world.
"""
pass
"""
Formally prove that: 1. Your adversary has an advantage of 1 - 2^-128.
---&---
[Answer here].
"""
from crypto.games.game_prf import GamePRF
from crypto.simulator.world_sim import WorldSim
if __name__ == '__main__':
g = GamePRF(F, key_len, block_len)
s = WorldSim(g, A)
print "The advantage of your adversary is ~" + str(s.compute_advantage())
