Poly1305-AES uses two per-connection keys $k$ (for AES) and $r$ (for Poly1305's compression function) and a per-message nonce n to execute. I've read the original paper on the implementation, and I ...
It's a well-known best practice to not use one key to both encrypt and MAC data. In my application, there are instances where I MAC a piece of data without having encrypted it first. Do I still need a ...