CompuServe Messages

One approach would be to store your strings in encrypted form and decrypt them just before they are displayed. A simple method which would deter the casual hacker (but not a determined code breaker) would be to exclusive or each character in the string with a fixed bit pattern. This garbles the characters but if you exclusive or the result with the same bit pattern again you get the original characters back. You would have to write a routine to do this, run all of your strings through it and save them in a file. Then the program would read the strings from the file and feed them through the decryption function before passing them to printf. A couple of things to bear in mind if you use this method. You probably can't use the line based file functions like fputs and fgets to read and write the file becase the encryption may create extra linefeeds in the strings. A possible method of marking the end of your encrypted strings would be to not encode the terminating null. If you do this (or if you use any string handling functions on the encrypted strings) chose a bit pattern for the key which is not the same as any ascii character you are using, this will make sure you don't get any extra nulls in the encrypted strings. Peter Wade Autopiloting from London, England