Scytale Cipher

Scytale Encryption uses a cylinder and a band characterized by its number of turns L of the band around the cylinder.

Example: Code DCODE with a band L=3.

The message is written along the cylinder, one letter per band, and when the end is reached, go to a new line.

If needed, the last line can be completed with another character, e.g. X or _.

Example:

The ciphered message is the band unrolled, (i.e the message read by column).

Example: The cipher text is DDCEO_

Scytale Decryption requires to know the number N of letters by turn of the band (the size of the cylinder), or L the number of turns around the cylinder.

Example: The ciphertext is DDCEO_ (6-character long) and the band is L=3, then N=2 (because 6/3=2).

Write the message on the band and wraps the band around the cylinder (of correct size) and the plain text should appear.

Example:

As it is a transposition cipher, the ciphered message has an index of coincidence similar to the language of the plain text.

One can crack Scytale by testing all possible size of the rectangle.

Scytale is a practical application of the Caesar Cipher.

8 to 6 centuries BC