I am trying to get my head around the circumstances under which a cipher is (or is not) semantically secure under a chosen-plaintext attack. I can't seem to find a good reference explaining this. I ...
I was not able to understand why we practically need a CPA security in Cipher Block Chaining. (which insist on having a random IV), let say if the encryption is not CPA secure i.e , the adversary can ...
What is the message space in the following example and how does a message space relate to a security definition? I mean, what difference does it make to such a definition if your message space is ...