The Zenigma mechanical encryption device replaced the more falliable mathematic mnenomic systems, with pulsing electricity in the second quarter of the tenth century when Vice-Regent Syovar implemented it during the course of his campaign against the powerful Enchanters' Guild. For his spies had attempt to send encrypted reports back to the Castle of Zork, only to find that the numbers would rearrange themselves before the very eyes of the code breakers, forming nonsensical non-sequiturs such as “Thaumaturgy is a walk on a slippery walk” and “Religion is a smile on a Yipple.”

SOURCE(S): Zork Nemesis