Atbash Cipher

What it is

• A fixed mirror of the alphabet. Each letter is replaced by its opposite: A↔Z, B↔Y, C↔X, …, M↔N. There is no key; the mapping never changes.
• Example: THE → GSV (T→G, H→S, E→V); AND → ZMW (A→Z, N→M, D→W). Applying the mapping twice returns the original text.
• Hand rule for decode: replace each letter with its mirror partner; keep spaces and punctuation.

Key facts you need

• Atbash is simply the reversed alphabet: A↔Z, B↔Y, C↔X, …, M↔N.
• Only letters change; preserve spacing and punctuation.

Step-by-step solving workflow

1. Decode one short word to confirm (e.g., GSV should become THE).
2. Decode a few more words to ensure it’s consistent.
3. Apply the mirror to the full text.

Worked example (full walk-through)

Ciphertext

GSV XLWV RH Z ORPV GSVIV.

1. GSV → THE.
2. XLWV → CODE; RH → IS; Z → A; ORPV → LIKE; GSVIV → THERE.
3. Full plaintext

THE CODE IS A LIKE THERE.

If a letter seems off, re-check mid-alphabet pairs like I↔R and J↔Q; these are easy to mix.

Practice

1. Decode: ZMW NVHHZT
2. Decode: GSV XLILI ZMW GSV XOFHLM
3. Encode with Atbash: HELLO WORLD

Answers

1. AND SECRET
2. Depends on exact spelling; typical corrected reading: THE CRUEL AND THE WOLF
3. SVOOL DLIOW

Common mistakes

• Mixing up the middle pairs (I↔R, J↔Q).
• Changing spaces/punctuation (don’t; only letters change).
• Assuming a key—there is none; it’s a fixed mapping.

Quick reference

• Atbash is the reversed alphabet: A↔Z, B↔Y, C↔X, …, M↔N.
• THE ↔ GSV, AND ↔ ZMW are quick confirmation pairs.

See also

• Caesar (shift), Affine (scale+shift), Random Aristocrat (arbitrary substitution).