# Tag Info

What you're describing is called a known-plaintext attack, and any secure encryption algorithm should prevent this. If we take an encryption function with no IV $C = ENC(M, K)$ we should get a system where knowing both $M$ and $C$ reveals nothing about $K$. We can expand this principal to $C = ENC(M \oplus IV, K)$ and simplify it back to the example without ...