International Association
for Cryptologic Research

A simple and practical hashing scheme based on Cyclic Redundancy Check (CRC) is presented. Similarly to previously proposed cryptographically secure CRCs, the presented one detects both, random and malicious, errors without increasing bandwidth. However, we use a product of irreducible polynomials instead of a single irreducible polynomial for generating the CRC. This is an advantage since smaller irreducible polynomials are easier to compute. The price we pay is that the probability that two different messages map into the same CRC increases. We provide a detailed quantitative analysis of the achieved security as a function of message and CRC sizes. The presented method seems to be particularly attractive for the authentication of short messages.