In this work, we settle the longstanding open question: we present the first multiparty NIKE protocol that is adaptively secure with no setup and in the standard model.
Our construction is based on indistinguishability obfuscation and obliviously-patchable puncturable pseudorandom functions, a new notion that we introduce.
We employ novel techniques of using indistinguishability obfuscation, which are interesting in their own right and which we believe would find wider applications in other settings. One such technique pertains overcoming, the somewhat inherent, drawback of non-adaptivity of the puncturing technique introduced by Sahai and Waters [STOC'14]. Central to this technique is our new notion of obliviously-patchable puncturable pseudorandom functions. We present a concrete construction of these pseudorandom functions using multilinear maps and their recent approximations -- the leveled-graded encoding schemes. Note that pseudorandom functions amount to an interactive assumption. We shall establish via a meta-reduction technique that, in natural settings, an interactive assumption is necessary (even with setup).Category / Keywords: adaptive security, key exchange Date: received 4 Nov 2014, last revised 21 Nov 2014 Contact author: vhvanshvansh at gmail com Available format(s): PDF | BibTeX Citation Note: Reorganized the Introduction slightly. Version: 20141121:192534 (All versions of this report) Short URL: ia.cr/2014/910 Discussion forum: Show discussion | Start new discussion