There's the British Museum cryptanalysis package which according to Chuck Hallenbech who wrote me about it earlier is pretty effective in doing its work. Simtel mirrors many years ago had some very basic encryption and decryption packages on them and those may have been removed. There's all kinds of password cracking utilities used by hackers to open up files that oughtn't be available to them too. If you ever get any of those, please first run them through with clamscan and if you get a good report proceed with caution. Finally, the data file formats handbook latest edition will probably provide a huge amount of help in certain instances. Get the latest edition though since it gets updated just about every year.
