It turns out that physical realization bears negatively and directly on the security of any cryptographic implementations, which means that the theoretical security of any mathematical cryptographic scheme in leakage free setting (a.k.a. black-box model) does not hold any more when it is implemented and running at physical realization level in leaky setting (e.g. in the context of side-channel attacks). However, it is not clear that whether or not the theoretical security of one leakage resilient cryptographic scheme will still remain secure with considering any details of mathematical realizations. In other words, whether or not the theoretical leakage resilience of one leakage resilient cryptographic construction will still keep unchanged and/or slightly changed, if this scheme is instantiated with cryptographic components that meet their claimed security properties.
In this paper, we try to answer this question of important theoretical values, by presenting attacks on three mathematical realizations of the leakage resilient ElGamal encryption scheme EG^* in the paper of E. Kiltz et al. at Asiacrypt2010. Our results convincingly indicate that mathematical realizations of EG^* really have significant destructive impact on its theoretical leakage resilience. This important discovery is not considered or neglected in previous work. Our results suggest that a leakage resilient scheme without considering the mathematical realization may not be secure any more.Category / Keywords: Leakage Resilient Cryptography, Mathematical Realization, PRNG, Lattice Date: received 12 Apr 2013, last revised 16 Sep 2013 Contact author: guangjunfan at 163 com Available format(s): PDF | BibTeX Citation Version: 20130916:074743 (All versions of this report) Discussion forum: Show discussion | Start new discussion