The Scytale (σκυτάλη) was used by Spartan generals around 400 BC. A parchment strip was wound around a rod of a specific diameter, the message was written along the rod, and when unwound the letters appeared in a scrambled order. Decryption required a rod of the same diameter. It is a pure transposition cipher: the ciphertext is a permutation of the plaintext letters. Only the number of letters that fit per turn (the diameter) is the key.
Plaintext written around a rod of diameter 4. Read down each column to get the ciphertext.
Try every possible diameter from 2 up to the ciphertext length. Click any row to apply that diameter.