Paper 2016/1083 Original: eprint.iacr.org/2016/1083 ↗

Constructions Secure against Receiver Selective Opening and Chosen Ciphertext Attacks

Abstract

In this paper we study public key encryption schemes of indistinguishability security against receiver selective opening (IND-RSO) attacks, where the attacker can corrupt some receivers and get the corresponding secret keys in the multi-party setting. Concretely: -We present a general construction of RSO security against chosen ciphertext attacks (RSO-CCA) by combining any RSO secure scheme against chosen plaintext attacks (RSO-CPA) with any regular CCA secure scheme, along with an appropriate non-interactive zero-knowledge proof. -We show that the leakage-resistant construction given by Hazay \emph{et al.} in Eurocrypt 2013 from weak hash proof system (wHPS) is RSO-CPA secure. -We further show that the CCA secure construction given by Cramer and Shoup in Eurocrypt 2002 based on the universal HPS is RSO-CCA secure, hence obtain a more efficient paradigm for RSO-CCA security.