Rail Fence

The railfence cipher is a transposition cipher that follows a simple rule for mixing up the characters in the plaintext to form the ciphertext. Although weak on its own, it can be combined with other ciphers, such as a substitution cipher, the combination of which is more difficult to break than either cipher on it's own. This is equivalent to using an un-keyed columnar transposition cipher.

Plaintext:

Key Rows:

Offset:

Ciphertext:
Rail Fence Layout: