Tools › Ciphers
Ciphers
Make and break puzzles and codes: classical ciphers from Caesar and ROT13 to Vigenère and Playfair, a cipher cracker, an Enigma machine, XOR, number and picture alphabets, and ways to hide a message in a picture or in plain text, and to find one.
Caesar / ROT13Shift letters along the alphabet, with ROT13, ROT5, ROT18 and ROT47, and every shift at once ranked by how English it reads.
Classical CiphersAtbash, Affine, keyword substitution, keyed Caesar, Vigenère, Beaufort, Autokey, Gronsfeld, Porta, one-time pad, Playfair, Four-square, Bifid, Trifid, Nihilist, Rail Fence, columnar, double and AMSCO transposition, route and scytale, Polybius, Bacon, ADFGX, ADFGVX and Pigpen, both ways as you type.
Image SteganographyHide a message or a small file inside a picture's pixels, optionally locked with a password, and reveal it again.
Cipher CrackerPaste a ciphertext and it tries every Caesar, Affine and Atbash key, finds likely Vigenère and Beaufort keys, and tries Rail Fence, with the most English results first; on request it also solves keyword substitutions (cryptograms) and columnar transpositions.
Enigma MachineA working Enigma I, M3 and M4, with rotors I–VIII, reflectors, ring settings and plugboard. Typing the ciphertext with the same settings decrypts it.
Hidden TextHide a secret inside ordinary text with invisible characters, and find, decode and remove invisible characters someone else has hidden.
Picture AlphabetsWrite text in pigpen, semaphore, maritime signal flags, Hexahue, Braille, Elder Futhark runes or Greek letters, and read it back by clicking the symbols you see.
Visual CryptographySplit a word or picture into two images of random noise. Either alone shows nothing; laid on top of each other, they reveal the secret.
Image EncryptionEncrypt a picture's pixels with a password into a viewable image of noise and back, or see why ECB mode leaks the outline.
XOR CipherXOR text, hex or Base64 with a repeating key, and break single-byte and repeating-key XOR by trying keys and scoring the results.
Bit-Plane InspectorLook at each bit of an image's red, green, blue and alpha on its own, pull out the data in the low bits, and compare two images pixel by pixel.
Number CodesText as the number codes puzzles use, A1Z26, A0Z25, the tap code, the phone keypad (multi-tap and T9) and Baudot, all at once, and each of them back to text; plus BCD and Gray code for numbers.
Guides
Making a puzzle, treasure hunt or escape roomBuild clues that have one answer: check anagrams and word clues, encode messages as pigpen, flags, Morse or Enigma, make a two-transparency reveal, and playtest it before anyone sees it.
Solving an unknown cipherFrom a page of gibberish to plain text: find what kind of cipher it is, read its letter statistics, then crack it or decrypt it with a key.