This invention proposes a dual reconfigurable smart surface (RIS)-assisted "one-time pad" secure
wireless communication method to address the problems of low
physical layer key generation rate and insufficient key rate to meet the requirements of one-time pad
data transmission in
wireless communication. This method constructs a controllable-random channel environment by deploying two N-unit RISs. It utilizes a multi-agent
reinforcement learning (MARL)
algorithm to jointly optimize the RIS phase shift and the number of key negotiation rounds, achieving a
dynamic balance between
data transmission rate and
key generation rate. Based on this, it achieves absolutely
secure communication for one-time pad
data transmission. First, the legitimate communicating parties (
Alice and Bob) construct a multipath random
wireless channel by controlling the dual RISs based on
channel reciprocity in time-division duplex (TDD) mode. Second, the MARL
algorithm (including a pre-training mechanism) is used to control and optimize the phase shift of the dual RISs and determine the optimal number of key negotiation rounds for one-time pad. Finally, the
physical layer key is generated through channel probing, channel
estimation, quantization negotiation, and privacy amplification. Before data transmission, the generated key is used to XOR the transmitted data, achieving lightweight
encryption of the transmitted data. This method significantly improves the
physical layer key generation rate, provides a feasible solution for realizing "one-time key" data transmission, and is applicable to various
wireless security communication scenarios such as
the Internet of Things,
the Internet of Vehicles, and
satellite communication. It can take into account both the complexity of
edge device deployment and real-time requirements.