About Atbash Cipher

Hebrew alphabet substitution — A↔Z, B↔Y — self-inverse. Part of the DevTools Surf developer suite. Browse more tools in the Security / Crypto collection.

Use Cases

• Cryptography students studying classical cipher history
• Puzzle designers creating multi-layer encoding challenges
• CTF competitors recognizing and decoding Atbash-encrypted flags
• History enthusiasts exploring biblical code references

Tips

• Atbash is self-inverse: encode and decode are the same
• Only alphabetic characters are substituted; numbers pass through
• Combine with other ciphers for layered encoding puzzles

Fun Facts

• The Atbash cipher originates from ancient Hebrew cryptography, with its name derived from the first, last, second, and second-to-last Hebrew letters: Aleph-Tav-Beth-Shin.
• Atbash appears in the Bible — the Book of Jeremiah uses it to encode 'Babel' as 'Sheshach' (Jeremiah 25:26), making it one of the oldest known ciphers in recorded history.
• Like ROT13, Atbash is an involution — applying it twice restores the original text — because the substitution A-Z, B-Y is perfectly symmetrical.

FAQ

What's Atbash?

Hebrew alphabet substitution: aleph↔tav, bet↔shin. In English: A↔Z, B↔Y, C↔X. Self-inverse — encryption and decryption are the same operation.

Is it secure?

Not at all. It's one of the earliest ciphers (~600 BC) and trivially reversible. Useful only for puzzles, games, and teaching substitution ciphers.

Why is it called self-inverse?

Because A↔Z is symmetric — applying it twice gets you back to the original. Same for Z↔A. So encrypting an Atbash ciphertext gives the plaintext.

What's its origin?

Hebrew scribes used it in biblical texts as a literary device — not for security. Appears in the book of Jeremiah.