I'm working on the development of a resonably secure software registration scheme, and thought that someone from the Cypherpunk list would be ideal for helping out. Sample code is even better, but general advice to do with the methodology and coding would be most appreciated. There is a program out there called PROTECT! EXE/COM, which does something on the lines of EXE encryption which has been brought up here. I've corresponded with the author and he won't release the code (understandably, he's worked very hard on it). Apparently what it does is (after you have run something like PKLITE on your executable) encapsulates the EXE file, encrypted, with CRC checks and debugger traps. He claims this is quite effective and has not had anyone come through with cracking it yet. Just thought I would mention this .... Unfortunately, that program is only for DOS/Windows. It would be NICE to have something like this working under UNIX, and I can't imagine that it would be that difficult, although it would most certainly be platform (assembly language) specific. Anyone have some ideas about how to implement such a beast? Thanks alot...