Atbash
Atbash was invented for the Hebrew alphabet and already appears in a few passages of the Bible. Its name comes from four Hebrew letters: aleph, tav, bet and shin, that is, the first, the last, the second and the second to last. That is the whole rule: the alphabet is read backwards. A becomes Z, B becomes Y, C becomes X, and so on.
It has no key, which makes it perfect for a first challenge: all you need is the alphabet written in two rows, once forwards and once backwards. And encoding and decoding are exactly the same thing.
Try it
Type a message and copy the result. Accents are dropped and the result is written in capitals. With the 27-letter alphabet, Ñ takes its place between N and O, and N, right in the middle, stays as it is.
Atbash has no key: each letter always becomes the same one.
35 of 600 characters
GLNLIILD DV LKVM GSV GIVZHFIV XSVHG
The key
Each letter in the top row becomes the letter under it, and the other way round.
| Letter | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Becomes | Z | Y | X | W | V | U | T | S | R | Q | P | O | N | M | L | K | J | I | H | G | F | E | D | C | B | A |
Printable worksheet
Practise this cipher on paper: a worksheet with the key and two exercises, ready to print or download with its answer key. Open the worksheet