Research On Wireless Physical Layer Key Generation Based On Received Signal Strength

Extracting the advantage from the wireless fading channel to generate a key for the actual security system is a promising field.The impulse response of the channel varies with path and time,and the channel has reciprocity during the coherence time of the channel.There is a high degree of correlation between legal channels in the coherence time and almost no correlation for eavesdropping channels that are more than a few wavelengths away.This provides an opportunity for improvements and additions to traditional encryption systems based on computational complexity security.Given that the lack of trusted third parties or the lack of a public key infrastructure is common in the future,it is necessary to study the ability and security of nodes to generate keys based on their own capabilities.This paper mainly studies the key generation method based on received signal strength,and the main work are as follows;The key generation process and the evaluation criteria for generating keys are described in detail.The key performance of Level-Crossing and adaptive secret bit generation is analyzed,and the algorithm is improved to be applied in low-speed mobile scenes.We set up several possible ways of moving the nodes,including uniform linear motion in the same direction and in the opposite direction,cross motion of the nodes,and the distance of the line of sight of the person walking on the node.The experiment measures the performance of the generated key from the aspects of key generation rate,key inconsistency rate,and entropy.The results show that our scheme effectively improves the key generation rate and passes the randomness test.In order to detect the attacker's correlation between the eavesdropping channel and the legitimate letter in the indoor environment.We set up three indoor environments that simulate the symmetrical position of the eavesdropper in space with legitimate users and the location on the strong line of sight.We designed the key generation protocol and used non-reciprocity compensation and multi-bit quantization scheme to effectively increase the key generation rate.