Columnar Transposition Cipher

Write plaintext in rows, then read columns in keyword order.

Columnar Transposition writes plaintext out in rows and reads ciphertext off in columns. The row length is the length of the keyword, and the plaintext is padded to fit the rectangle under the keyword. The columns are reordered alphabetically, then read off in that order.

This implementation pads plaintext so its length is a multiple of the key length.

Plaintext