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The Atbash cipher is one of the oldest known substitution ciphers, originally used for the Hebrew alphabet — it simply mirrors each letter to its opposite position in the alphabet.
This tool applies the Atbash cipher to any text, mapping A to Z, B to Y, and so on.
How it works
Enter your text. Every letter is mirrored to its opposite position in the alphabet (A becomes Z, B becomes Y, and so on), while non-letter characters are left unchanged.
- Enter text.
- Click Calculate to see your results.
Examples
Mirroring "Hello"
"Hello" becomes "Svool" when run through the Atbash cipher.
Who should use it
- Word puzzles and simple text obfuscation for games.
- Teaching the concept of substitution ciphers.
Industry applications
- Cryptography education
- Games and puzzles
Advantages
- Extremely simple to apply and verify by hand.
- Self-reciprocal — the same operation both encodes and decodes.
Limitations
- No key at all, so it provides no real security whatsoever.
Common mistakes to avoid
- Expecting a separate "decode" mode — Atbash decoding is identical to encoding since the mapping is its own inverse.
- Assuming Atbash offers any real security, since there's no secret key involved at all.
Best practices
- Use Atbash for puzzles, wordplay, or teaching the concept of substitution ciphers — it has no practical security use.
Tips
- Because Atbash is self-reciprocal, you can verify your result is correct by running the output back through the tool and checking that you get the original text back.