Time Slot Allocation for RIS-Assisted Physical Layer Key Generation in OTP

The one time pad (OTP) technique can provide information-theoretic security and physical layer key generation (PLKG) is a promising candidate for OTP. In the joint PLKG and OTP scheme, channel probing, information reconciliation and encrypted packet transmission all need to occupy channel time. In this paper, we propose a time slot allocation scheme for PLKG in OTP. We divide the process of OTP into three stages: channel probing, information reconciliation and encrypted packet transmission. Then, we analyze the secret key capacity and the time slot cost of the whole process. Under the premise of ensuring safety, we give a time slot reduction strategy to reduce time slot cost. Meanwhile, we propose a time slot allocation optimization algorithm to realize the strategy. Simulation results verify that our scheme can significantly reduce the time slot cost.