Question

If I am employing the Vigenere cipher to encode the message `WeAttackAtDawn', and my codeword is `SicSemperTyrannis', what will be the third letter of my encoded message?

Answer 1

Using the Vigenère cipher with the keyword 'SicSemperTyrannis' to encrypt 'WeAttackAtDawn,' the third letter of the encoded message is shifted by three positions, resulting in 'D'.

Step-by-step explanation:

The Vigenère cipher is a method of encrypting alphabetic text using a simple form of polyalphabetic substitution. To encode a message, each letter of the plaintext is shifted along some number of places with regards to a repeating keyword. In this case, if the codeword is 'SicSemperTyrannis' and the message is 'WeAttackAtDawn', the third letter of the encoded message is determined by taking the third letter of the message, 'A', and shifting it by the number of positions in the alphabet corresponding to the third character of the codeword, 'c', which is 3. Thus, the third letter of the encoded message would be 'D'.