Skytale
In 5th century B.C, the Spartans of Greece used a cylindrical staff, called a Skytale, to pass secret messages around in the military. This could be perceived as the maiden attempt in military cryptography. A narrow sheet of papyrus was wound around the skytale spirally and the secret message was written on the wound papyrus along the length of the skytale. Once the papyrus was unwound from the staff, the letters on the papyrus would make no sense: the message was thus encrypted. This encrypted message was now sent through a messenger to the recipient, who would use a similar staff with the same diameter to decrypt the message by winding the papyrus on the staff.
