cipher decoder
pick a cipher and type. the result updates as you go, and caesar, vigenère and rail fence can be cracked without the key.
questions
how does vigenère cracking work?
it measures how often letters repeat at every spacing to find the key length, then treats each key letter as its own caesar shift and picks the one that makes english letter frequencies line up. it needs a few sentences of ciphertext; short texts can fool it.
which cipher is my text in?
a quick guide: only dots and dashes is morse, numbers from 1 to 26 are A1Z26, pairs of digits from 1 to 5 are tap code or polybius, groups of five A and B are bacon, and letters that look like scrambled english are caesar, atbash or vigenère. if you are not sure, the mystery text decoder tries all of them.
what is the phone keypad cipher?
letters as presses on an old phone keypad: 2 is abc, 3 is def, and so on. multi-tap writes h as 44 because h is the second letter on key 4. the other style writes the key and then the position, so h is 42.
what is bacon's cipher?
each letter becomes five A or B symbols, like a 5-bit code. the A and B can hide in anything with two forms, like lowercase and capital letters, so normal looking text can carry a message in its capitals.