Encrypt and decrypt text with the Atbash cipher by mirroring letters across the selected alphabet. One of the oldest known substitution ciphers in classical cryptography.
HELLO WORLD
SVOOL DLIOW
Alphabet: English. Atbash replaces letters with mirrored positions.
SVOOL DLIOW
HELLO WORLD
Alphabet: English. Applying Atbash again restores original text.
HELLO, WORLD!
SVOOL, DLIOW!
Letters are mirrored while spaces and punctuation remain unchanged.
ABCDEFGHIJKLMNOPQRSTUVWXYZ
ZYXWVUTSRQPONMLKJIHGFEDCBA
A complete Atbash alphabet mapping example.
The Atbash cipher replaces every letter with its opposite position in the alphabet. In the English alphabet, A becomes Z, B becomes Y, C becomes X, and so on.
Unlike most classical ciphers, Atbash does not require a key. The substitution is fixed and always follows the same mirrored alphabet pattern.
Atbash is self-reciprocal, meaning the same operation is used for both encryption and decryption. Applying the cipher twice restores the original text.
Atbash originated in the ancient Hebrew alphabet and is considered one of the earliest known substitution ciphers. It was used by reversing the order of alphabet letters and replacing each symbol with its mirrored counterpart.
Today, Atbash is primarily used for education, puzzles, and historical demonstrations of classical cryptography.
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Classical reciprocal cipher based on a keyword.
Vigenere-style classical cipher that uses a numeric key.
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