This online tool breaks Vigenère ciphers without knowing the key. At first glance the Vigenère Cipher appears to be unbreakable, due to its use of up to 26 different cipher alphabets. We recall that a Caesar k-shift is the circular permutation which replaces each letter of the alphabet by the letter k places later (with wrap around). I've already written a cease cypher, so I have a pretty decent idea of how to program most of the encryption. Ideally, you would use a random key that is longer than the plaintext, so it never repeats, which guarantees that the ciphertext cannot be decoded without the key. The term Cipher is standard term for an encryption algorithm in the world of cryptography.
