Bounded Leakage-Resilient Functional Encryption with Hidden Vector Predicate

Recent research shows that many public-key or identity-based encryption schemes are vulnerable to side-channel attacks on the keys by the interaction of an adversary with a physical device. To tolerate the possible key leakage, leakage-resilient cryptography models a class of leakage output by allowing the adversary to be able to specify a computable leakage function and obtaining the partial keys or other possibly internal states from the output of function. In this article, we propose a leakage-resilient hidden-vector encryption (HVE) scheme that supports the predicate operators such as conjunction, disjunction, comparison, range query and subset query, etc. The proposed scheme is leakage-resilient attribute-hiding secure in the sense that the adversary cannot only obtain the tokens of non-match vectors but also learn amount of key information of the vector that matches the challenge vector. To the best of our knowledge, this is the first HVE that supports token-leakage resilience. We prove the security with a series of computationally indistinguishable games that uses the dual system encryption mechanism. We also analyze and discuss the performance of leakage bound parameters and leakage fraction in the practical security level. Finally, we also give an extensive scheme to achieve the security of both attribute-hiding and payload-hiding, and analyze the performance in larger alphabets.