This directory contains a description and software for the RIPEMD-160 and RIPEMD-128 hash functions. The implementations are written for the sole purpose of documentation. No optimization whatsoever is performed: only readability and portability were kept in mind. ripemd160.ps.gz: description of RIPEMD-160 and RIPEMD-128. This has also been published in Fast Software Encryption, LNCS 1039, D. Gollmann (Ed.), pp. 71-82. This version differs from the published version in that a figure has been added, four small mistakes in the pseudo-code of Appendix A have been corrected, and the order in which the permutations pi and rho^i are applied in Section 3 have been exchanged. In addition, the hash value of the message consisting of 1 million 'a' characters has been added to Appendix B for both RIPEMD-160 and RIPEMD-128. rmd160.c: source code for RIPEMD-160 rmd160.h: include file for RIPEMD-160. Make sure that the types byte, word and dword are respectively 8, 16, and 32-bit unsigned quantities. rmd128.c: source code for RIPEMD-128 rmd128.h: include file for RIPEMD-128. Make sure that the types byte, word, and dword are respectively 8, 16, and 32-bit unsigned quantities. hashtest.c: driver for both RIPEMD-160 and RIPEMD-128. Default is RIPEMD-160. For compilation with rmd128.c define RMDsize=128. Command line arguments of hashtest: any combination of filename -- compute hash code of file read binary -sstring -- print string & hashcode -t -- perform time trial -x -- execute standard test suite, ASCII input A bug in the RMDonemillion() function of this driver has been corrected. Any comments on the description or the implementation can be mailed to antoon.bosselaers@esat.kuleuven.ac.be