XORrior is a file encryption system using the simple - but, if used properly, powerful - XOR operator.

If you use a (truly) random key file which is at least as big as the source file, the XOR encryption will be unbreakable. You can obtain truly random files by, for example, recording radio noise with your soundcard. XORrior can encrypt Gigabyte-sized files in a few minutes on a modern computer.