Scytale

A scytale (also spelled "skytale") is a tool used to make a transposition cipher, consisting of a cylinder with a strip of paper wound around it. The recipient has a rod of the same diameter, on which he wraps the paper to read the message. It has the considerable advantage of being fast and not prone to mistakes a nice property when on the battlefield, but the even more considerable disadvantage of being easily 'broken' if its use is suspected. Since the strip of paper hints strongly at the method, the cyphertext would have to be transferred to something less suggestive, somewhat reducing the advantage noted. The ancient Greeks, particularly, the Spartans, are said to have used this cypher to communicate during military campaigns.

In July 1998, an article in Cryptologia magazine suggested that the story of the scytale may be a myth.