International Association for Cryptologic Research
In this paper, the authors introduce a general notion of Functional Proxy-Re-Encryption (F-PRE), where a wide class of Functional Encryption (FE) is combined with Proxy-Re-Encryption (PRE) mechanism. The PRE encryption system should reveal minimal information to a proxy, in particular, hiding parameters of re-encryption keys and of original cipher-texts which they manipulate is highly desirable. They first formulate such a fully-anonymous security notion of F-PRE including usual payload-hiding properties. They then propose the first fully-anonymous Inner-Product PRE (IP-PRE) scheme, whose security is proven under the DLIN assumption and the existence of a strongly unforgeable one-time signature scheme in the standard model.