In this paper, we take another look at the linear-complexity PFE protocol by Katz and Malka (ASIACRYPT'11): We propose several optimizations and split the protocol in different phases that depend on the function and inputs respectively. We show that HE-based PFE is practical when instantiated with state-of-the-art ECC and RLWE-based homomorphic encryption. Our most efficient implementation outperforms the most recent UC-based PFE implementation of Alhassan et al. (JoC'20) in communication for all circuit sizes and in computation starting from circuits of a few thousand gates already.
Category / Keywords: cryptographic protocols / Private function evaluation, homomorphic encryption, secure computation. Original Publication (with minor differences): ESORICS 2020 Date: received 8 Jul 2020, last revised 14 Sep 2020 Contact author: kiss at encrypto cs tu-darmstadt de,holz@encrypto cs tu-darmstadt de Available format(s): PDF | BibTeX Citation Version: 20200914:204233 (All versions of this report) Short URL: ia.cr/2020/853