D4.4. Annual Report on FE Schemes for richer functionalities Y1

The concept of functional encryption (FE) is a generalization of standard encryption, which allows users to delegate to third parties the computation of certain classes of functions of the encrypted data by generating specific secret keys for these functions.

This report describes two contributions made in the context of FENTEC. First, we describe the unbounded attribute-based encryption scheme proposed by Chen et al. with constant-size public parameters under static assumptions in bilinear groups. This scheme defines the current state of the art in the area of unbounded attribute-based encryption. Second, we describe the inner-product predicate encryption schemes introduced by Chen et al. The proposed schemes achieve adaptive security and full attribute-hiding in the prime-order bilinear group setting and improve current results by Okamoto et al.