yadrychnikovnicolay/jscipher

jsCipher is a personal crypto project based on the Vigenère cipher with the exception that the key must be as long as the text to encode, making it not vulnerable to the Kasiski analysis, like the original would.

jsCipher - What to do and how it works :

It's a Vigenère cipher re-creation, except that your key has to be of the same length that your message, which makes it not vulnerable to the Kasiski analysis, except if you create a pattern in your key on purpose.

To encrypt, just enter your message(there is a button to show all the supported chars) and your key(or generate it randomly) and click on encrypt, it will divide each letter in the message and the key into an array of letters and then add them together. To decrypt, paste the encrypted message you got and enter the same key you used.

Try it out