def decryption_time(storage, q_list):
iterations = 1
timings = []
aggregate_time = []
aggregate_size = []
no_of_bits = len(list(bin(storage['n'])[2:]))+1
kpabe = KPabe(group)
for q in q_list:
check = True
timing = 0.0
gen_timing = 0.0
for i in xrange(iterations):
more_than_equal, less_than = generate_range(storage, q)
start = time.clock()
policy = policy_less_than('A', less_than, no_of_bits) + " and " + policy_more_than_equal('A', more_than_equal, no_of_bits)
secret_key = kpabe.keygen(storage['master_public_key'], storage['master_key'], policy)
end = time.clock()
gen_timing += end-start
cipher_text = storage['cipher'][more_than_equal:less_than]
plain_text = storage['plain'][more_than_equal:less_than]
start = time.clock()
result = [kpabe.decrypt(ct, secret_key) for ct in cipher_text]
end = time.clock()
timing+=end-start
if (plain_text!=result):
check = False
aggregate_time.append((q, gen_timing/iterations))
aggregate_size.append((q, getsizeof(pickle.dumps(objectToBytes(secret_key, group)))))
if (check==True):
timings.append((q, timing/iterations))
else:
timings.append((q, 'error'))
return timings
def kpabe_decrypt(group, mpk, deckey, ctxt):
"""Decrypts a ciphertext using the Lewmko2008rws KP-ABE Scheme.
The plaintext will be returned iff the set of attributes used to
generate the cipher-text can be satisfied by the policy within the
decryption key.
@param group The `PairingGroup` used within the underlying crypto.
@param mpk The Master Public Key of type `mk_t`.
@param deckey The decryption key of type `sk_t`.
@param ctxt The `bytearray` resulting from `io.open` or `io.IOBytes`
containing the ciphertext.
@return A `bytearray` containing the plaintext.
@throw PebelDecryptionException if deckey cannot satisfy the
policy within the ciphertext.
"""
kpabe = KPabe(group)
ptxt = io.BytesIO()
iv = ctxt.read(AES.block_size)
session_key_size = struct.unpack('<Q', ctxt.read(struct.calcsize('Q')))[0]
session_key_ctxt = bytesToObject(ctxt.read(session_key_size), group)
session_key = kpabe.decrypt(session_key_ctxt, deckey)
if session_key:
symcipher = AES.new(sha(session_key)[0:32], AES.MODE_CFB, iv)
for b in read_data(bin_data=ctxt, chunksize=AES.block_size):
ptxt.write(symcipher.decrypt(b))
ptxt.flush()
return ptxt.getvalue()
else:
raise PebelDecryptionException("Unable to decrypt given ciphertext")
def decryption_time(storage, q_list):
iterations = 5
timings = []
aggregate_time = []
aggregate_size = []
no_of_bits = len(list(bin(storage['n'])[2:]))+1
kpabe = KPabe(group)
for q in q_list:
print "q"
print q
check = True
timing = 0.0
gen_timing = 0.0
for i in xrange(iterations):
# print "iterations"
# print i
more_than_equal, less_than = generate_range(storage, q)
print "more_than_equal"
print more_than_equal
print "less_than"
print less_than
start = time.clock()
policy = policy_less_than('A', less_than, no_of_bits) + " and " + policy_more_than_equal('A', more_than_equal, no_of_bits)
print "policy"
print policy
secret_key = kpabe.keygen(storage['master_public_key'], storage['master_key'], policy)
end = time.clock()
gen_timing += end-start
cipher_text = storage['cipher'][more_than_equal:less_than]
plain_text = storage['plain'][more_than_equal:less_than]
start = time.clock()
assert group.InitBenchmark(), "failed to initialize benchmark"
group.StartBenchmark(["Mul", "Exp", "Pair", "Div", "Granular"])
result = [kpabe.decrypt(ct, secret_key) for ct in cipher_text]
group.EndBenchmark()
end = time.clock()
msmtDict = group.GetGeneralBenchmarks()
print("<=== General Benchmarks ===>")
print("Results := ", msmtDict)
timing+=end-start
if (plain_text!=result):
check = False
aggregate_time.append((q, gen_timing/iterations))
aggregate_size.append((q, getsizeof(pickle.dumps(objectToBytes(secret_key, group)))))
if (check==True):
timings.append((q, timing/iterations))
else:
timings.append((q, 'error'))
return timings
def benchmark():
groupObj1 = PairingGroup('MNT224')
groupObj2 = PairingGroup('MNT224')
ekpabe = EKPabe(groupObj1)
kpabe = KPabe(groupObj2)
t1_s = 0
t1_k = 0
t1_e = 0
t1_d = 0
t2_s = 0
t2_k = 0
t2_e = 0
t2_d = 0
attributes = ['ONE', 'TWO', 'THREE', 'FOUR']
policy = 'THREE and (ONE or TWO)'
msg1 = b"Some Random Message"
msg2 = groupObj2.random(GT)
for b in range(4):
start = clock()
(epk, emk) = ekpabe.setup(attributes)
t1_s += clock() - start
start = clock()
(pk, mk) = kpabe.setup()
t2_s += clock() - start
start = clock()
emykey = ekpabe.keygen(epk, emk, policy)
t1_k += clock() - start
start = clock()
mykey = kpabe.keygen(pk, mk, policy)
t2_k += clock() - start
for i in range(50):
start = clock()
eciphertext = ekpabe.encrypt(epk, msg1, attributes)
t1_e += clock() - start
start = clock()
ciphertext = kpabe.encrypt(pk, msg2, attributes)
t2_e += clock() - start
start = clock()
erec_msg = ekpabe.decrypt(eciphertext, emykey)
t1_d += clock() - start
start = clock()
rec_msg = kpabe.decrypt(ciphertext, mykey)
t2_d += clock() - start
assert msg1 == erec_msg
assert msg2 == rec_msg
print("yct14 s=%s k=%s e=%s d=%s" % (t1_s, t1_k, t1_e, t1_d))
print("lsw08 s=%s k=%s e=%s d=%s" % (t2_s, t2_k, t2_e, t2_d))
def testKPabe(self):
groupObj = PairingGroup('MNT224')
kpabe = KPabe(groupObj)
(pk, mk) = kpabe.setup()
policy = '(ONE or THREE) and (THREE or TWO)'
attributes = [ 'ONE', 'TWO', 'THREE', 'FOUR' ]
msg = groupObj.random(GT)
mykey = kpabe.keygen(pk, mk, policy)
if debug: print("Encrypt under these attributes: ", attributes)
ciphertext = kpabe.encrypt(pk, msg, attributes)
if debug: print(ciphertext)
rec_msg = kpabe.decrypt(ciphertext, mykey)
assert msg == rec_msg
if debug: print("Successful Decryption!")
def testKPabe(self):
groupObj = PairingGroup('MNT224')
kpabe = KPabe(groupObj)
(pk, mk) = kpabe.setup()
policy = '(ONE or THREE) and (THREE or TWO)'
attributes = ['ONE', 'TWO', 'THREE', 'FOUR']
msg = groupObj.random(GT)
mykey = kpabe.keygen(pk, mk, policy)
if debug: print("Encrypt under these attributes: ", attributes)
ciphertext = kpabe.encrypt(pk, msg, attributes)
if debug: print(ciphertext)
rec_msg = kpabe.decrypt(ciphertext, mykey)
assert msg == rec_msg
if debug: print("Successful Decryption!")
def decryption_time(storage, q_list):
iterations = 1
timings = []
aggregate_time = []
aggregate_size = []
no_of_bits = len(list(bin(storage['n'])[2:])) + 1
kpabe = KPabe(group)
for q in q_list:
check = True
timing = 0.0
gen_timing = 0.0
for i in xrange(iterations):
more_than_equal, less_than = generate_range(storage, q)
start = time.clock()
policy = policy_less_than(
'A', less_than, no_of_bits) + " and " + policy_more_than_equal(
'A', more_than_equal, no_of_bits)
secret_key = kpabe.keygen(storage['master_public_key'],
storage['master_key'], policy)
end = time.clock()
gen_timing += end - start
cipher_text = storage['cipher'][more_than_equal:less_than]
plain_text = storage['plain'][more_than_equal:less_than]
start = time.clock()
result = [kpabe.decrypt(ct, secret_key) for ct in cipher_text]
end = time.clock()
timing += end - start
if (plain_text != result):
check = False
aggregate_time.append((q, gen_timing / iterations))
aggregate_size.append(
(q, getsizeof(pickle.dumps(objectToBytes(secret_key, group)))))
if (check == True):
timings.append((q, timing / iterations))
else:
timings.append((q, 'error'))
return timings
def kpabe_decrypt(group, mpk, deckey, ctxt):
"""Decrypts a ciphertext using the Lewmko2008rws KP-ABE Scheme.
The plaintext will be returned iff the set of attributes used to
generate the cipher-text can be satisfied by the policy within the
decryption key.
@param group The `PairingGroup` used within the underlying crypto.
@param mpk The Master Public Key of type `mk_t`.
@param deckey The decryption key of type `sk_t`.
@param ctxt The `bytearray` resulting from `io.open` or `io.IOBytes`
containing the ciphertext.
@return A `bytearray` containing the plaintext.
@throw PebelDecryptionException if deckey cannot satisfy the
policy within the ciphertext.
"""
kpabe = KPabe(group)
ptxt = io.BytesIO()
iv = ctxt.read(AES.block_size)
session_key_size = struct.unpack('<Q',
ctxt.read(struct.calcsize('Q')))[0]
session_key_ctxt = bytesToObject(ctxt.read(session_key_size), group)
session_key = kpabe.decrypt(session_key_ctxt, deckey)
if session_key:
symcipher = AES.new(sha(session_key)[0:32], AES.MODE_CFB, iv)
for b in read_data(bin_data=ctxt, chunksize=AES.block_size):
ptxt.write(symcipher.decrypt(b))
ptxt.flush()
return ptxt.getvalue()
else:
raise PebelDecryptionException("Unable to decrypt given ciphertext")
