- n-KDM-projection security, an extension of circular security, where the adversary may also ask for encryptions of negated secret key bits;
– a (1-o(1)) resilience rate in the bounded-memory leakage model of Akavia et al. (TCC 2009); and
– Auxiliary-input security against subexponentially-hard functions.
We introduce homomorphic weak pseudorandom functions, a homomorphic version of the weak PRFs proposed by Naor and Reingold (FOCS ’95) and use them to realize our base encryption scheme. We obtain homomorphic weak PRFs under assumptions including subgroup indistinguishability (implied, in particular, by QR and DCR) and homomorphic hash-proof systems (HHPS). As corollaries of our results, we obtain (1) a projection-secure encryption scheme (as well as a scheme with a (1-o(1)) resilience rate) based solely on the HHPS assumption, and (2) a unifying approach explaining the results of Boneh et al (CRYPTO ’08) and Brakerski and Goldwasser (CRYPTO ’10). Finally, by observing that Applebaum’s KDM amplification method (EUROCRYPT ’11) preserves both types of leakage resilience, we obtain schemes providing at the same time high leakage resilience and KDM security against any fixed polynomial-sized circuit family.Category / Keywords: public-key cryptography / KDM Security, circular security, leakage resilience Original Publication (with minor differences): IACR-PKC-2016 Date: received 23 Jul 2015, last revised 23 Feb 2016 Contact author: mhaji at uvic ca Available format(s): PDF | BibTeX Citation Version: 20160223:222126 (All versions of this report) Short URL: ia.cr/2015/741 Discussion forum: Show discussion | Start new discussion