Leakage-Resilient Inner-Product Functional Encryption in the Bounded-Retrieval Model.

We propose a leakage-resilient inner-product functional encryption scheme (IPFE) in the bounded-retrieval model (BRM). This is the first leakage-resilient functional encryption scheme in the BRM. In our leakage model, an adversary is allowed to obtain at most l-bit knowledge from each secret key. And our scheme can flexibly tolerate arbitrarily leakage bound l, by only increasing the size of secret keys, while keeping all other parts small and independent of l.