Search for a tool
Atbash Cipher

Tool to decrypt/encrypt with Atbash (Mirror code), a substitution cipher replacing the first letter of the alphabet with the last, the second with the penultimate etc.

Results

Atbash 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!

Feedback and suggestions are welcome so that dCode offers the best 'Atbash Cipher' tool for free! Thank you!

# Atbash Cipher

## Atbash Encoder

### What is Atbash cipher? (Definition)

Atbash cipher (also called mirror cipher or backwards alphabet or reverse alphabet) is the name given to a monoalphabetical substitution cipher which owes its name and origins to the Hebrew alphabet.

Atbash replaces each letter with its symmetrical one in the alphabet, that is, A becomes Z, B becomes Y, and so on.

### How to encrypt using Atbash cipher?

Atbash encryption uses a substitution alphabet and its reciprocal, a combination of the normal alphabet and its reverse alphabet (mirrored).

Example: The latin alphabet ABCDEFGHIJKLMNOPQRSTUVWXYZ and its reverse: ZYXWVUTSRQPONMLKJIHGFEDCBA are combine in the substitution table:

 Normal ABCDEFGHIJKLMNOPQRSTUVWXYZ Reverse ZYXWVUTSRQPONMLKJIHGFEDCBA

Encryption consists in replacing letters from the first with letters from the other one, with is equivalent to replace the first letter of the alphabet A with the last one Z, the second one B with the penultimate Y etc.

Example: MIRROR becomes NRIILI

### How to decrypt Atbash cipher?

Decryption is identical to encryption because of the reversible alphabet (due to the symmetry of the backwards alphabet)

Example: ZGYZHS is decrypted ATBASH

dCode offers an encoder and a decoder, but they are actually one and the same Atbash converter.

### How to recognize an Atbash ciphertext?

An Atbash ciphertext has a coincidence index similar to an unencrypted text.

If the encryption used the classical latin alphabet, letters V,G,R,L,M appear the most frequently.

Otherwise the presence of Hebrew characters or a reference to the Dead Sea can be a clue.

The notions of mirror, reflection, opposite, axis, direction, word written in reverse (hsabta) are also clues.

### Why is this cipher called 'Atbash'?

In the Hebraic alphabet, aleph (first letter) was replaced by tav (last letter) and beth (second letter) with shin (second last), etc. Initials make A,T,B,SH.

### How is the Atbash number used in the Hebrew Bible?

The number Atbash is mentioned in the Hebrew Bible, notably in the book of Jeremiah (chapter 25, verse 26 and chapter 51, verse 41). It is used to replace the name of certain kings and countries with their coded equivalents.

### What dictionary words still exist when encrypted?

There are a small number of words that have an existing Atbash equivalent in the English dictionary.

Example: GIRTH & TRIGS, GIRL & TRIO, GLOW & TOLD, HOLD & SLOW, HORN & SLIM, WILD & DROW, ZARA & AZIZ

In Hebrew, this situation is more common (notably because the alphabet has no vowels).

### What are Atbash variants?

Atbash is adaptable to any alphabet, so using the Hebrew alphabet is possible.

The atbash cipher is equivalent to an affine cipher with $a = -1$ and $b = -1$

The atbash cipher is equivalent to a monoalphabetic substitution with the alphabet ZYXWVUTSRQPONMLKJIHGFEDCBA

### When was Atbash invented?

The exact origin of the Atbash cipher is uncertain, but it is known to have been used in ancient Israel around the 6th or 5th century BC.

## Source code

dCode retains ownership of the "Atbash Cipher" source code. Except explicit open source licence (indicated Creative Commons / free), the "Atbash Cipher" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, breaker, translator), or the "Atbash Cipher" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and all data download, script, or API access for "Atbash Cipher" are not public, same for offline use on PC, mobile, tablet, iPhone or Android app!
Reminder : dCode is free to use.

## Cite dCode

The copy-paste of the page "Atbash Cipher" or any of its results, is allowed (even for commercial purposes) as long as you credit dCode!
Exporting results as a .csv or .txt file is free by clicking on the export icon
Cite as source (bibliography):
Atbash Cipher on dCode.fr [online website], retrieved on 2024-09-10, https://www.dcode.fr/atbash-cipher

## Need Help ?

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