A Framework and Compact Constructions for Non-monotonic Attribute-Based Encryption.
Shota Yamada, Nuttapong Attrapadung, Goichiro Hanaoka, Noboru Kunihiro · 2014
In this paper, we propose new non-monotonic attribute-based encryption schemes with com-pact parameters. The first three schemes are key-policy attribute-based encryption (KP-ABE) and the fourth scheme is ciphertext-policy attribute-based encryption (CP-ABE) scheme. • Our first scheme has very compact ciphertexts. The ciphertext overhead only consists of two group elements and this is the shortest in the literature. Compared to the scheme by Attrapadung et al. (PKC2011), which is the best scheme in terms of the ciphertext overhead, our scheme shortens ciphertext overhead by 33%. The scheme also reduces the size of the master public key to about half. • Our second scheme is proven secure under the decisional bilinear Diffie-Hellman (DBDH) assumption, which is one of the most standard assumptions in bilinear groups. Compared to the non-monotonic KP-ABE scheme from the same assumption by Ostrovsky et al. (ACM-CCS’07), our scheme achieves more compact parameters. The master public key and the ciphertext size is about the half that of their scheme. • Our third scheme is the first non-monotonic KP-ABE scheme that can deal with unbounded