Columnar Transposition Cipher Decoder and Encoder

In a columnar transposition cipher, the message is written in a grid of equal length rows, and then read out column by column. The columns are chosen in a scrambled order, decided by the encryption key. Since transposition ciphers doesn't affect the letter frequencies, it can be detected through frequency analysis. Like other transposition ciphers, it can be attacked by moving letters around and anagramming. Also it can be attacked using brute-force methods if the key isn't long enough.

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Columnar Transposition Cipher Tool

You must enter the message.

Knowing the encryption key

You must enter the encryption key.

Not knowing the key


Need to customize the output? Click the Options button.


Key Text

Still not seeing the correct result? Then try experimenting with the Auto Decrypt options or use the Cipher Identifier Tool.


Options

Text processing


Grid


        

Features

  • The columnar transposition cipher is an example of transposition cipher.
  • It is simple enough to be possible to carry out by hand.
  • It can encrypt any characters, including spaces and punctuation, but security is increased if spacing and punctuation is removed.
  • The message does not always fill up the whole transposition grid. The remaining of the transposition grid can then optionally be filled with a padding character (regular columnar transposition cipher), or left blank (irregular columnar transposition cipher).

Sample Columnar Transposition Cipher Text

Code-breaking is not only fun, but also a very good exercise for your brain and cognitive skills. Why don’t you try breaking this example cipher:

laaoa ztfse eetdp nebda befie dhpeh ruqtr faath waose ekwoy udiin uoafn koial niree mrwza stdeh sesas mnkgd ilnnt sltoo draum edeow leh