Hardware vs software

RE this topic, there are methods (Merkle's for example) where you can get multiple megabytes per second through a good encryption algorithm in a CPU. DES is kind of optimised for doing it in hardware, so don't take how slow it is in software as the limit for good encryption. Keith (Gnu posted the paper a long time ago in sci.crypt, but I don't know if I can find it on my newer system.)