# Why is stateful CTR slightly better than stateless CTR? Does the adversary know the value of counter in CTR mode of operation?

This might be a stupid question but is really fundamental in my understanding of CTR (I'm a newbie to cryptography theory).

For CPA security, the adversary only knows the IV, and may query the oracle for random values of IV+$$ctr^*$$ where $$ctr^*$$ is the counter.

For stateful CTR, what do we assume is predictable - the nonce or the counter?