abenc_unmcpabe_yahk14

Non-monotonic CP-ABE (YAHK14)

Authors: Shota Yamada, Nuttapong Attrapadung, Goichiro Hanaoka, Noboru Kunihiro

Title: “A Framework and Compact Constructions for Non-monotonic Attribute-Based Encryption”

Published in: Public-Key Cryptography (PKC) 2014, Pages 275-292

Available from: http://eprint.iacr.org/2014/181 (Section 7)

Notes: Supports non-monotonic access structures (with negation)

Scheme Properties

• Type: ciphertext-policy attribute-based encryption (public key)

• Setting: Bilinear pairing group of prime order

• Assumption: Complex q-type assumption

Implementation

Authors:

al, artjomb

Date:

07/2015

class abenc_unmcpabe_yahk14.CPABE_YAHK14(groupObj, verbose=False)

Bases: ABEnc

>>> from charm.toolbox.pairinggroup import PairingGroup,ZR,G1,G2,GT,pair
>>> group = PairingGroup('SS512')
>>> cpabe = CPABE_YAHK14(group)
>>> msg = group.random(GT)
>>> attributes = ['2', '3'] # must be integer strings
>>> access_policy = '2 and !1' # must be integer strings
>>> (master_public_key, master_key) = cpabe.setup()
>>> secret_key = cpabe.keygen(master_public_key, master_key, attributes)
>>> cipher_text = cpabe.encrypt(master_public_key, msg, access_policy)
>>> decrypted_msg = cpabe.decrypt(master_public_key, secret_key, cipher_text)
>>> msg == decrypted_msg
True

decrypt(pp, sk, ct)

encrypt(pp, message, policy_str)

exp(value)

keygen(pp, mk, S)

randomMessage()

setup()

abenc_unmcpabe_yahk14.main()