Which of the statements below are correct

The basic BB$84$ protocol uses non$-$orthogonal states to encode and transmit the key by employing rectilinear and diagonal bases of photon polarizations.

The operating parameters of the quantum key distribution are not affected by the quality of the quantum channel connecting the sender and the receiver.

The E$91$ protocol tests violation of the Bell inequality to detect eavesdropping.

In QKD$,$ the key is encrypted using an unconditionally secure one$-$time pad $($OTP$)$ encryption method.