All previous efficient VES schemes in the standard model are either secure under standard assumptions (such as the computational Diffie-Hellman assumption) with large verification (or secret) keys or secure under \emph{(non-standard) dynamic $q$-type assumptions} (such as the $q$-strong Diffie-Hellman extraction assumption) with short verification keys. Our construction is the first efficient VES scheme with short verification (and secret) keys secure under \emph{a standard assumption (DLIN)}.
As by-products of our VES scheme, we construct new obfuscators for ES/EVES based on our new VES scheme. They are more efficient than previous obfuscators with respect to the public key size. Previous obfuscators for EVES are secure under non-standard assumption and use zero-knowledge (ZK) proof systems and Fiat-Shamir heuristics to obtain non-interactive ZK, i.e., its security is considered in the random oracle model. Thus, our construction also has an advantage with respect to assumptions and security models. Our new obfuscator for ES is obtained from our new obfuscator for EVES.
Category / Keywords: cryptographic protocols / verifiably encrypted signature, obfuscation, encrypted verifi- ably encrypted signature, decisional linear assumption Original Publication (in the same form): IACR-PKC-2013 Date: received 16 Mar 2015 Contact author: nishimaki ryo at lab ntt co jp Available format(s): PDF | BibTeX Citation Note: This is the IACR version. Version: 20150319:073047 (All versions of this report) Short URL: ia.cr/2015/248 Discussion forum: Show discussion | Start new discussion