A Simple and Unified Method of Proving Indistinguishability
Recently Bernstein  has provided a simpler proof of indistinguishability of CBC construction  which is giving insight of the construction. Indistinguishability of any function intuitively means that the function behaves very closely to a uniform random function. In this paper we make a unifying and simple approach to prove indistinguishability of many existing constructions. We first revisit Bernstein’s proof. Using this idea we can show a simpler proof of indistinguishability of a class of DAG based construction , XCBC , TMAC , OMAC  and PMAC . We also provide a simpler proof for stronger bound of CBC  and a simpler proof of security of on-line Hash-CBC . We note that there is a flaw in the security proof of Hash-CBC given in . This paper will help to understand security analysis of indistinguishability of many constructions in a simpler way.
KeywordsOutput Function Input Function Random Function Simple Proof Sink Node
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