Security analysis of epsilon-almost dual universal2 hash functions: smoothing of min entropy vs. smoothing of Rényi entropy of order 2
This work addresses security analysis for cryptography, but it appears incremental as it focuses on clarifying differences between existing entropy smoothing methods for a recently proposed hash function class.
The paper evaluates the security performance of epsilon-almost dual universal2 hash functions, a new class, by analyzing differences between smoothing of min entropy and smoothing of Rényi entropy of order 2 under L1 distinguishability and modified mutual information criteria.
Recently, $\varepsilon$-almost dual universal$_2$ hash functions has been proposed as a new and wider class of hash functions. Using this class of hash functions, several efficient hash functions were proposed. This paper evaluates the security performance when we apply this kind of hash functions. We evaluate the security in several kinds of setting based on the $L_1$ distinguishability criterion and the modified mutual information criterion. The obtained evaluation is based on smoothing of Rényi entropy of order 2 and/or min entropy. We clarify the difference between these two methods.