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.
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You must enter the encryption key.
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Auto Solve Options


Instructions

You can decode (decrypt) or encode (encrypt) your message with your key. If you don't have any key, you can try to auto solve (break) your cipher.

Settings
  • Language: The language determines the letters and statistics used for decoding, encoding and auto solving.
  • Min/Max Key Length: This is the search range for keys when auto solving a cipher.
  • Max Results: This is the maximum number of results you will get from auto solving.
  • Spacing Mode: This is about the spaces (word breaks) in the text. In most cases it should be set to Automatic. In case a specific letter (for instance X) is used as word separator, set it to Substitute.

Not seeing the correct result? Try Auto Solve or use the Cipher Identifier Tool.


Auto Solve results

Score Key Text

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


Grid

Enter the key and click decode or encode to show.

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:

ieesd ouhsm osnbi wmfmo amnem myeeh ctefo taiel espte yyeie waree oycna msina eohto crtvh nevbt eomli iwotl nrhuo sharr wtite omriv llsyu yntav we