Vigenère Cipher

What is the Vigenère cipher?

It is a classical polyalphabetic cipher where a keyword shifts each letter by a different amount. The same keyword encrypts and decrypts, so it is called a symmetric cipher.

How do I encrypt a message?

Type the plain text, enter a keyword and keep Encrypt selected. Each letter is shifted by the corresponding keyword letter, repeating the keyword until the message ends.

How is text decrypted?

Select Decrypt and enter the same keyword that was used to encrypt. The process is reversed and the original text is restored.

Does it support Turkish characters?

Yes. The alphabet includes Turkish letters like Ç, Ğ, İ, Ö, Ş and Ü, so Turkish text encrypts and decrypts correctly. Other characters are kept unchanged.

Is this secure for real secrets?

No. The Vigenère cipher is easy to break with modern computers and is used for learning and fun rather than protection. Do not rely on it for sensitive data.