Indifferentiable Security Analysis of choppfMD, chopMD, a chopMDP, chopWPH, chopNI, chopEMD, chopCS, and chopESh Hash Domain Extensions

Abstract

We provide simple and unified indifferentiable security analyses of choppfMD, chopMD, a chopMDP (where the permutation $P$ is to be xored with any non-zero constant.), chopWPH (the chopped version of Wide-Pipe Hash proposed in \cite{Lucks05}), chopEMD, chopNI, chopCS, chopESh hash domain extensions. Even though there are security analysis of them in the case of no-bit chopping (i.e., $s=0$), there is no unified way to give security proofs. All our proofs in this paper follow the technique introduced in \cite{BeDaPeAs08}. These proofs are simple and easy to follow