One-way hash functions with changeable parameters

Abstract

In this paper, four new algorithms for improvements of MD5 and SHA-Keyed/Unkeyed MD5 and Keyed/Unkeyed SHA are proposed. We change the mode of fixed retrieval of the parameters to that of dynamic retrieval of the parameters by applying a mapping between the index phrase and the parameter table. As shown in the experimental result, with 1% degradation of performance, comparing to the original algorithms, dynamic retrieval of parameters can be achieved. We believe that the security can be increased under the improvements. (C) 1999 Elsevier Science Inc. All rights reserved.