Automatic Caesar cipher breaker (JavaScript)
Program
| Shift: | ||||
| Best guesses: |
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Description
Type or paste the ciphertext, then pressBreak code
. The ciphertext is decrypted automatically with the best-guessed shift. If the result is incorrect, you can manually try all the different shifts by pressingUp
/Down
, or by clicking on a table row.
The case is preserved and non-letters are unchanged by encryption or decryption. The automatic decryption is done by trying all 26 possible shift values and calculating the cross-entropy with English letter frequencies (unigram model). The algorithm works best on English text, but in practice it works well on other European languages too.
Thesource code is available for viewing.