Search for a tool
Double Transposition Cipher

Tools to decrypt/encrypt with double transposition cipher, as its names indicates, it uses two transposition ciphers, with one or two keys, and applied on lines or columns or both.

Results

Double Transposition Cipher -

Tag(s) : Cryptography, Transposition Cipher

dCode and you

dCode is free and its tools are a valuable help in games, puzzles and problems to solve every day!
You have a problem, an idea for a project, a specific need and dCode can not (yet) help you? You need custom development? Contact-me!


Team dCode read all messages and answer them if you leave an email (not published). It is thanks to you that dCode has the best Double Transposition Cipher tool. Thank you.

Double Transposition Cipher

Sponsored ads

Double Transposition Decoder







Double Transposition Encoder







Tools to decrypt/encrypt with double transposition cipher, as its names indicates, it uses two transposition ciphers, with one or two keys, and applied on lines or columns or both.

Answers to Questions

How to encrypt using Double Transposition cipher?

Encryption uses twice a transposition cipher, usually the first transposition is in columns, and the second in lines.

Example: Encrypt DCODE with twice the key KEY

DCO
DEX

Example: The grid is filled with X and permutated a first time

CDO
EDX

Example: The intermediate ciphered message is CDOEDX. Make a second transposition, but with lines

\12
KCD
EOE
YDX

Example: The grid becomes, after the second permutation

\12
EOE
KCD
YDX

The ciphertext is then obtained by reading the grid in lines, from left to right and from top to bottom.

Example: The ciphered message is then OECDDX

How to decrypt Double Transposition cipher?

Decryption requires to know both keys and the kind of transposition used for each (line or column)

Example: The crypted message is OECDDX, transposed with 1 column transposition and 1 line transposition with two identical keys : KEY.

The crypted message gets two reversed transposition, in the opposite order of the original order, to get back the plain text.

Example: Si the grid is

\12
EOE
KCD
YDX

Example: It becomes, avec a first reversed permutation in lines

\12
KCD
EOE
YDX

Example: The intermediate message is then CDOECX, it gets another reversed permutation, in column

CDO
EDX

Example: The grid becomes

DCO
DEX

Example: The original plain text is DCODEX.

How to recognize Double Transposition ciphertext?

A message encrypted by Double Transposition has a frequency analysis and a coincidence index normal.

The number of letters in the message is not a prime number.

How to decipher Double Transposition without keys?

It is possible to find the key length by analyzing the prime decomposition of the text length.

By writing the text in the grid, permute the columns in order to find words on each lines, beginning with common bigrams (such as TH, HE, IN, etc.).

To find the second permutation, it is easier, because lines are already in plain text.

What are the variants of the Double Transposition cipher?

It is possible to shuffle lines or columns in the desired order.

When Double Transposition have been invented?

No date of known author.

Ask a new question

Source code

dCode retains ownership of the source code of the script Double Transposition Cipher online. Except explicit open source licence (indicated Creative Commons / free), any algorithm, applet, snippet, software (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or any function (convert, solve, decrypt, encrypt, decipher, cipher, decode, code, translate) written in any informatic langauge (PHP, Java, C#, Python, Javascript, etc.) which dCode owns rights can be transferred after sales quote. So if you need to download the online Double Transposition Cipher script for offline use, for you, your company or association, see you on contact page !

Questions / Comments


Team dCode read all messages and answer them if you leave an email (not published). It is thanks to you that dCode has the best Double Transposition Cipher tool. Thank you.


Source : https://www.dcode.fr/double-transposition-cipher
© 2017 dCode — The ultimate 'toolkit' to solve every games / riddles / geocaches. dCode