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Caesar Cipher Decoder & Encoder
Shift :
About Caesar cipher Decoder Online :
Caesar cipher is a basic letters substitution algorithm. It takes as input a message, and apply to every letter a particular shift. This shift used to be 3 (Caesar shift), according to history, when it was used by Caesar to encrypt war messages (so for example a would become d, b wille be e, and so on and so forth). Of course you can choose any shift you want. This is basically a modulo 26 addition; Caesar cipher, as
Polybius Square cipher
, is a monoalphabetical cipher. Like the others of this kind, the problem of this cipher is its really poor security. To break it, you can, like I do here, apply every shift to the Caesar cipher, and see if there's one that makes sense.
The other way to break it is by looking to
letters frequency
. For example we know that in english the e is very frequent, then the t, then a, etc. Then you look to couples of letters, for example et, at, th, etc, and finally you can break the code.
A special kind of Caesar cipher is
Rot13 cipher
which is basically the same except that the shift is 13 instead of the caesar shift of 3.