I am interested in learning and understanding cryptography and its application in every day life. One thing I can't seem to get my head around is encrypting plaintext using a block mode such as CFB. I want to use a Caesar block cipher in CFB mode to encrypt the following plaintext:
lucozade with a key:
So in this case, I get that using the Caeser block cipher the ciphertext for
lucozade would be
oxfrcdgh as the letters have shifted three places to the right. What I can't do is this encryption using CFB mode. How do I go about doing that? Like would I have to use the ciphertext
oxfrcdgh as the IV?
Any help would be great