Complete Columnar

Description

The simplest version of a transposition cipher is the Complete Columnar Transposition cipher in which all columns are of equal length and form a complete rectangle or block. The plaintext is written into the block horizontally and then each column is read off vertically to form the cipher. The order in which the columns are read is determined by the alphabetic order of the letters of a keyword. The number of letters in the keyword also defines the width of the rectangle used.

Example

Key: CHILD (13452)

Plaintext: Growing old is mandatory. Growing up is optional.

CHILD

13452

GROWI

NGOLD

ISMAN

DATOR

YGROW

INGUP

ISOPT

IONAL

Ciphertext: GNIDY IIIID NRWPT LRGSA GNSOO OMTRG ONWLA OOUPA

Solving

Solving method: Brute force search.

After selecting the Complete Columnar cipher, the cipher period can be selected from the Period drop down menu in the Cipher Settings ribbon group. The default setting of 0 will result in all periods in the keyword range set in the Options window being tested. For more in-depth searching select a specific key length.