Peter van der Linden's Guide to Linux: A Lesson in Encryption, Part 1 (Linux Journal)
The mathematical qualities that PKE relies on have a beautiful symmetry to them, and PKE rocked the worlds of computer science and encryption when it appeared in the 1970s. Government scientists in Britain's GCHQ eavesdropping and phone-tapping center later claimed that they had invented the technique some years earlier, but kept it secret! Indeed, they did uncover some of the theory, but it was clear that the spies of GCHQ had not grasped its practical significance."