Keyed Vigenere

Keyed Viginere is the cipher that is mostly likely used on the EnderBroz server. The passphrase is almost always "EnderBroz". When it is not, It will be something like "Sphaxvale".

Vigenère cipher Vigenère cipher is a series of Caesar ciphers where each letter shift depends on a key word. Vigenère ciphers use a Vigenère square, like the one below, to encrypt the message. The square is 26 rows of Caesar ciphers starting with a zero letter shift. On each additional row, the shift of the letters is increased by 1.

As Vigenère ciphers a bit more complicated, consider the following example: we want to encrypt the message GABBYGOOSTEWISCOOL and use ENDERBROZ as the key. We would repeat the key word until it matched the length of the message (in this case, ENDERBROZENDERBROZ). Using the table above, we match the message letter to a row and the corresponding key letter to a column and find the letter at their intersection on the table. For example, the row starting with G and the column starting with E intersect at K. The row starting with A and the column starting with N intersect at N. So using our message and the key, the we'd create the following cipher:

Note that any time the message is A, the cipher letter will be the same as the key letter and vice versa.

Another way to think of Vigenère ciphers is that each letter of the key corresponds to a Caesar shift number (A=0, B=1, C=2, etc.) and for each letter of the message you form a Caesar shift based on the corresponding key letter.