Search for a tool
ROT-13 Cipher

Tool to decrypt/encrypt with rot13. ROT-13 cipher is a particular case of the Caesar cipher, where the shift is equal to 13, this allow the cipher to be reciprocal.

Results

ROT-13 Cipher -

Tag(s) : Substitution Cipher

Share
dCode and more

dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day!
A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!

Please, check our dCode Discord community for help requests!
NB: for encrypted messages, test our automatic cipher identifier!

Thanks to your feedback and relevant comments, dCode has developed the best 'ROT-13 Cipher' tool, so feel free to write! Thank you!

# ROT-13 Cipher

## ROT13 Encoder

### How to encrypt using Rot-13?

Encryption with Rot-13 replaces a letter by another one placed 13 ranks after in the alphabet. Each letter is therefore shifted by 13 positions in the English alphabet. The correspondance table is:

 ABCDEFGHIJKLM NOPQRSTUVWXYZ

Example: DCODE is crypted QPBQR with ROT-13

This is a special case of the Caesar cipher (and more generally shift ciphers)

### How to decrypt Rot-13 cipher?

Rot-13 decryption is identical to encryption, due to the reciprocal substituting alphabet used:

 NOPQRSTUVWXYZ ABCDEFGHIJKLM

Example: URYYB becomes HELLO.

Rot-13 has the same function for encryption and decryption, it is said to be involutive.

### How to recognize ROT-13 ciphertext?

Frequency analysis shows a shift of 13 letters (The E is replaced by an R, which should be the most present letter).

A message encoded by Rot13 has an index of coincidence similar to the language of the plain text.

The ROT13 code has been widely popularized on usenet groups and discussion forums, for example as a method of spoil.

### What are the variants of the Rot-13 cipher?

Rot-13 is in fact a Caesar cipher with a shift of 13. As this code only works with letters, it was proposed to use it with the Rot5 for numbers or the Rot47 for ASCII values.

### What is the particularity of ROT13 Cipher?

An offset of 13 allows the encryption to be reversible. The encryption and decryption method are identical. Applying 2 consecutive encryptions (2 shifts of 13) heads to find the original text.

## Source code

dCode retains ownership of the online 'ROT-13 Cipher' tool source code. Except explicit open source licence (indicated CC / Creative Commons / free), any 'ROT-13 Cipher' algorithm, applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or any 'ROT-13 Cipher' function (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and no data download, script, copy-paste, or API access for 'ROT-13 Cipher' will be for free, same for offline use on PC, tablet, iPhone or Android ! dCode is free and online.

## Need Help ?

Please, check our dCode Discord community for help requests!
NB: for encrypted messages, test our automatic cipher identifier!