The keyed Caesar cipher is a variant of the Caesar Cipher that provides increased protection. Instead of having all letters in alphabetical order, it starts with a code word (the encryption key). Unused letters are then added after the code word. If the code word is blank, it behaves exactly like an ordinary Caesar Cipher.

Keyed Caesar Cipher Tool

🌎

Instructions

You can decode (decrypt) or encode (encrypt) your message with your key. If you don't have any key, you can try to auto solve (break) your cipher.

Settings
  • Language: The language determines the letters and statistics used for decoding, encoding and auto solving.
  • Iterations: The more iterations, the more time will be spent when auto solving a cipher.
  • Max Results: This is the maximum number of results you will get from auto solving.
  • Spacing Mode: This is about the spaces (word breaks) in the text. In most cases it should be set to Automatic. In case a specific letter (for instance X) is used as word separator, set it to Substitute.

Auto Solver options

Knowing the encryption key

🔑#
You must enter the encryption key.
🔑T
You must enter the encryption key.
This field is for output. You should type in the input field instead.

Not able to find the correct result? Try Auto Solve or use the Cipher Identifier Tool.


Auto Solve results

Score Key Text

Still not seeing the correct result? Then try experimenting with the Auto Solve settings or use the Cipher Identifier Tool.

Features

Caesar cipher, and variants of it, are often used in easy geocaching mystery caches, and easy logic puzzles.

Sample Keyed Caesar Cipher

Code-breaking is not only fun, but also a very good exercise for your brain and cognitive skills. Why don’t you try breaking this example cipher:

rsut ut hgk tguk rsl rub aookzgb mon um al jgbbor plr ro rsl ygbk al tsgyy hl jgnnulk ubro rsl joibrnd om rsl aujwlk aurjs om rsl altr gbk tsl auyy lbjsgbr it gbk zgwl it sln tygqlt

See also: Code-Breaking tools | Adfgvx cipher | Adfgx cipher | Affine cipher | Atbash cipher | Baconian cipher | Beaufort cipher | Bifid cipher | Caesar cipher | Columnar transposition | Cryptogram | Double transposition | Enigma machine | Four-square cipher | Gronsfeld cipher | One-time pad | Pigpen cipher | Playfair cipher | Rail fence cipher | Rot13 | Route transposition | Substitution cipher | Trifid cipher | Variant beaufort cipher | Vigenere cipher