On existence of robust combiners for cryptographic hash functions?

Information Technologies - Applications and Theory 2009.

计算机科学;

Michal Rja·sko

Others  :  http://ceur-ws.org/Vol-584/paper10.pdf
PID  :  42657

学科分类：计算机科学（综合）

来源: CEUR

【 摘 要 】

A (k; l)-robust combiner for collision resistanthash functions is a construction, which takes l hash func- tions and combines them so that if at least k of the compo- nents are collision resistant, then so is the resulting com- bination. A black-box (k; l)-robust combiner is robust com- biner, which takes its components as black-boxes. A trivial black-box combiner is concatenation of any (l¡k+1) of the hash functions. Boneh and Boyen [1] followed by Pietrzak [3] proved, that for collision resistance we cannot do much better that concatenation, i.e. there does not exist black box (k; l)-robust combiner for collision resistance, whose output is signi¯cantly shorter that the output of the trivial com- biner. In this paper we analyze whether robust combiners for other hash function properties (e.g. preimage resistance and second preimage resistance) exist. Key words: Cryptographic hash function, robust com-