Proxy re‐encryption via indistinguishability obfuscation

Abstract

AbstractIn this paper, we present a proxy re‐encryption (PRE) scheme via an indistinguishability obfuscation ( ) by adding two algorithms to the public key encryption scheme by Sahai and Waters' (STOC 2014). Although a re‐encryption function from one public key to another can be considered as a randomized functionality on the underlying plaintext and that functionality can be achieved by using a probabilistic by Canetti et al. (TCC2015), we need a sub‐exponential to construct the probabilistic . In our construction, we need not the probabilistic but the standard . In addition, our proposed PRE scheme has some good properties. That is, unidirectional re‐encryption, unbounded multi‐hop re‐encryption, constant‐size ciphertext, and fast decryption. To the best of our knowledge, this is the first construction of a multi‐hop and unidirectional PRE scheme. Copyright © 2016 John Wiley & Sons, Ltd.