Paper 2017/489
Multi Collision Resistant Hash Functions and their Applications
Itay Berman and Akshay Degwekar and Ron D. Rothblum and Prashant Nalini Vasudevan
Abstract
Collision resistant hash functions are functions that shrink their input, but for which it is computationally infeasible to find a collision, namely two strings that hash to the same value (although collisions are abundant). In this work we study multi-collision resistant hash functions (MCRH) a natural relaxation of collision resistant hash functions in which it is difficult to find a t-way collision (i.e., t strings that hash to the same value) although finding (t-1)-way collisions could be easy. We show the following: - The existence of MCRH follows from the average case hardness of a variant of Entropy Approximation, a problem known to be complete for the class NISZK. - MCRH imply the existence of constant-round statistically hiding (and computationally binding) commitment schemes. In addition, we show a blackbox separation of MCRH from any one-way permutation
Metadata
- Available format(s)
- Category
- Foundations
- Publication info
- Preprint. MINOR revision.
- Keywords
- collision resistant hashingentropy approximation
- Contact author(s)
- ronr @ mit edu
- History
- 2017-09-26: revised
- 2017-05-31: received
- See all versions
- Short URL
- https://ia.cr/2017/489
- License
-
CC BY