|
Decentralized Ciphertext-Policy
Attribute-Based Encryption: A Post-Quantum Construction 1University
of Asia Pacific, Dhaka,
Bangladesh shahriar.rahman@uap-bd.edu
2KDDI
Research, Inc., Saitama, Japan {basu, kiyomoto}@kddi-research.jp
Abstract In Ciphertext Policy
Attribute-Based Encryption (CP-ABE) system, a set of attributes is associated
with the private keys of each user. Also, the ciphertext
is attached with a policy which is defined over that set of attributes. A
user can decrypt the ciphertext if the ciphertext’s policy is satisfied by the attributes
associated hith her private key. Traditional CP-ABE
schemes, based on number theoretic problems, rely on a trustworthy central
authority. But in many distributed applications it is expected that such
authorities should be decentralized to avoid the risks of single-point
failure. While the number theory-based hardness problems are prone to quantum
attacks, lattice-based hardness problems can resist such attacks. In this
paper, we construct a Decentralized Ciphertext-Policy
Attribute-Based Encryption (DCP-ABE) scheme. Under this scheme, any
participating entity can act as an authority by creating a public key. The athority utilizes the users’ attributes to generate the
private keys for them. Any user can encrypt data in terms of any monotone
access structure over attributes issued from any chosen set of authorities.
Hence the protocol does not depend on any central authority. We utilize
Learning With Errors over Rings (R-LWE) as the underlying hardness assumption
for te protocol. The proposed post-quantum protocol
achieves security under selective-set model whereby adversaries are allowed
to corrupt any authority only statically through adaptive key queries. Keywords: Security, CP-ABE, Decentralized,
Lattice +: Corresponding author: Mohammad Shahriar
Rahman Department of Computer Science and Enginering,
University of Asia Pacific, Dhaka 1215, Bangladesh. Tel: +8802-58157091(Ext. 707), Web: https://sites.google.com/site/msrahman1662 Journal
of Internet Services and Information Security
(JISIS), 7(3): 1-16, August 2017
[pdf] DOI: 10.22667/JISIS.2017.08.31.001 |