I would write a companion program that works like this: $ protector -lock filename.exe
and $ protector -unlock filename.exe the -lock switch would simply get the file size of filename.exe then generate a random chunk of data the same size, xor it with filename.exe and write the chunk data to a thumbdrive. filename.exe would now be 'garbage' the -unlock switch would then just read in the chunk of data from the thumbdrive then xor filename.exe with it to restore the file. this will stop most anyone from getting at filename.exe without the thumbdrive -- http://mail.python.org/mailman/listinfo/python-list