A substitution cipher swaps every letter for another letter and keeps that swap for the whole message. The text still looks like text — same word lengths, same spacing, same doubled letters — it just isn't in English yet.
Free tool Have one to decode right now? Use the Atbash Cipher toolWord shapes survive. If you can see one- and two-letter words, an apostrophe, or the same letter doubled in the middle of a word, you are almost certainly looking at a substitution.
Atbash The alphabet is reversed against itself: A becomes Z, B becomes Y.
TREASURE MAP
mirror
GIVZHFIV NZK
Every letter has been swapped for another one, and the same swap is used all the way through. Letter shapes stay put — word lengths and spacing are still real clues. This one is Atbash. The key: mirror. The alphabet is reversed against itself: A becomes Z, B becomes Y. Apply the key to the first three letters and they resolve to T R E. The answer was TREASURE MAP.
Start with the short words and the most common letter. In English that letter is usually E, and a lone letter is usually A or I. Two or three correct guesses tend to collapse the rest of the message on their own.
These have closed, so each one carries the full solution. Play them for practice — archive days never touch a streak.
Every letter has been swapped for another one, and the same swap is used all the way through. Letter shapes stay put — word lengths and spacing are still real clues. This one is Atbash. The key: mirror. The alphabet is reversed against itself: A becomes Z, B becomes Y. Apply the key to the first three letters and they resolve to L O O. The answer was LOOK BEHIND THE FALLS.
A review day — the cipher's name was withheld, so step one was working out which of the week's techniques was in play. Every letter has been swapped for another one, and the same swap is used all the way through. Letter shapes stay put — word lengths and spacing are still real clues. This one is Atbash. The key: mirror. The alphabet is reversed against itself: A becomes Z, B becomes Y. Apply the key to the first three letters and they resolve to B R I. The answer was BRING A LANTERN AND ROPE.
Every letter has been swapped for another one, and the same swap is used all the way through. Letter shapes stay put — word lengths and spacing are still real clues. This one is Atbash. The key: mirror. The alphabet is reversed against itself: A becomes Z, B becomes Y. Apply the key to the first three letters and they resolve to N O O. The answer was NO ONE HAS FOUND IT YET.
Every letter has been swapped for another one, and the same swap is used all the way through. Letter shapes stay put — word lengths and spacing are still real clues. This one is Atbash. The key: mirror. The alphabet is reversed against itself: A becomes Z, B becomes Y. Apply the key to the first three letters and they resolve to T H E. The answer was THE LEDGER NEVER LIES.
One a day, three guesses, and a streak that breaks the moment you miss one. Today’s is cipher #46.