md5 module is implemented as a C extension module in CPython. As this is currently not included in IronPython, I wrote a tiny wrapper around System.Security.Cryptography. Here it is in case you want it too. http://sparcs.kaist.ac.kr/~tinuviel/devel/fepy/md5.py It's under 30 lines! It should be trivial to adapt this to other hash algorithms. Seo Sanghyeon