def generate_ciphertext_keys(n):
storage = {}
storage['n'] = n
kpabe = KPabe(group)
more_than = 1
storage['plain'] = [group.random(GT)]
storage['cipher'] = [group.random(GT)]
no_of_bits = len(list(bin(n)[2:]))+1
print "no_of_bits"
print no_of_bits
storage['master_public_key'], storage['master_key'] = kpabe.setup()
frames_attribute = (num_to_attribute('A', i, no_of_bits) for i in xrange(1, n+1))
print "frames_attribute"
print frames_attribute
for i in xrange(n):
plain = group.random(GT)
storage['plain'].append(plain)
storage['cipher'].append(kpabe.encrypt(storage['master_public_key'], plain, frames_attribute.next()))
# ct = storage['cipher'][1:n+1]
# result = [kpabe.decrypt(cipher_text, secret_key) for cipher_text in ct]
# print 'lol', result
# print storage['plain'][1:n+1]
return storage
def generate_ciphertext_keys(n):
storage = {}
storage['n'] = n
kpabe = KPabe(group)
more_than = 1
storage['plain'] = [group.random(GT)]
storage['cipher'] = [group.random(GT)]
no_of_bits = len(list(bin(n)[2:])) + 1
storage['master_public_key'], storage['master_key'] = kpabe.setup()
frames_attribute = (num_to_attribute('A', i, no_of_bits)
for i in xrange(1, n + 1))
for i in xrange(n):
plain = group.random(GT)
storage['plain'].append(plain)
storage['cipher'].append(
kpabe.encrypt(storage['master_public_key'], plain,
frames_attribute.next()))
# ct = storage['cipher'][1:n+1]
# result = [kpabe.decrypt(cipher_text, secret_key) for cipher_text in ct]
# print 'lol', result
# print storage['plain'][1:n+1]
return storage
def kpabe_encrypt(group, mpk, ptxt, attributes):
"""Encrypts a plaintext using the Lewmko2008rws KP-ABE Scheme.
@param group The `PairingGroup` used within the underlying crypto.
@param mpk The master public key of type `mk_t`.
@param ptxt The `bytearray` resulting from io.open or `io.IOBytes`
containing the plaintext.
@param attributes The set of `str` attributes used to encrypt the
plaintext.
@return The encrypted data returned as a `bytearray`.
"""
kpabe = KPabe(group)
session_key = group.random(GT)
session_key_ctxt = kpabe.encrypt(mpk, session_key,
[a.upper() for a in attributes])
ctxt = io.BytesIO()
iv = Random.new().read(AES.block_size)
symcipher = AES.new(sha(session_key)[0:32], AES.MODE_CFB, iv)
ctxt.write(bytes(iv))
session_key_ctxt_b = objectToBytes(session_key_ctxt, group)
ctxt.write(struct.pack('Q', len(session_key_ctxt_b)))
ctxt.write(session_key_ctxt_b)
for b in read_data(bin_data=ptxt, chunksize=AES.block_size):
ctxt.write(symcipher.encrypt(b))
ctxt.flush()
return ctxt.getvalue()
def kpabe_encrypt(group, mpk, ptxt, attributes):
"""Encrypts a plaintext using the Lewmko2008rws KP-ABE Scheme.
@param group The `PairingGroup` used within the underlying crypto.
@param mpk The master public key of type `mk_t`.
@param ptxt The `bytearray` resulting from io.open or `io.IOBytes`
containing the plaintext.
@param attributes The set of `str` attributes used to encrypt the
plaintext.
@return The encrypted data returned as a `bytearray`.
"""
kpabe = KPabe(group)
session_key = group.random(GT)
session_key_ctxt = kpabe.encrypt(mpk,
session_key,
[a.upper() for a in attributes])
ctxt = io.BytesIO()
iv = Random.new().read(AES.block_size)
symcipher = AES.new(sha(session_key)[0:32], AES.MODE_CFB, iv)
ctxt.write(bytes(iv))
session_key_ctxt_b = objectToBytes(session_key_ctxt, group)
ctxt.write(struct.pack('Q' ,len(session_key_ctxt_b)))
ctxt.write(session_key_ctxt_b)
for b in read_data(bin_data=ptxt, chunksize=AES.block_size):
ctxt.write(symcipher.encrypt(b))
ctxt.flush()
return ctxt.getvalue()
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!")