Atbash Cipher

Each letter is replaced by its mirror in the alphabet (A to Z, B to Y, etc.).

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Each letter is replaced by its mirror in the alphabet (A to Z, B to Y, etc.).

The Atbash cipher is an ancient Hebrew substitution cipher that replaces each letter with the letter at the opposite end of the alphabet. A becomes Z, B becomes Y, C becomes X, and so on. The pattern is symmetric: encoding and decoding use the same operation.

A to Z, B to Y, C to X, D to W, E to V, F to U, G to T, H to S, I to R, J to Q, K to P, L to O, M to N

HELLO -> SVOOL
CAT -> XZG
WIZVM -> DREAM

How to recognize it

Each letter maps to its 'mirror' position
A always becomes Z, Z always becomes A
Encoding and decoding are identical operations

Common mistakes

Confusing middle letters (L->O, M->N)
Not recognizing the symmetric pattern
Forgetting that the same operation encodes and decodes

Step-by-step walkthrough

Encode 'HELLO' using the Atbash cipher

H is the 8th letter. Its mirror is the 8th from the end = S
E is the 5th letter. Its mirror is the 5th from the end = V
L is the 12th letter. Its mirror is the 12th from the end = O
L again maps to O
O is the 15th letter. Its mirror is the 15th from the end = L

Answer: SVOOL

Practice guidance

Coding & Decoding