Research On Physical Layer Key Generation Method Based On Optical Fiber Channel Characteristics

Optical fiber communication is an important infrastructure for carrying information transmission.Illegal parties obtain transmission data through eavesdropping,interference and other means,disrupting normal transmission and posing a threat to data security.Traditional cryptography has been unable to cope with the increasing computing power of illegal parties,and physical layer key generation technology has attracted the attention of researchersThis paper fully investigates the technical solutions of physical layer security at home and abroad,especially the technical solutions of physical layer key generation and distribution.On the basis of previous technical solutions,based on the coherent optical orthogonal frequency division multiplexing(CO-OFDM)system,to study the scheme of extracting Fibre Channel features to generate keys.The specific work and innovations are as follows:First,the method of attacking the optical fiber communication system is classified and discussed,and the possibility of extracting the characteristics of the optical fiber channel as the random source of the key is studied.Using the pre-shared symbols that are quantified by the channel characteristics,the information difference between the legal party and the illegal party is amplified by removing the mismatch step,thereby improving the key generation rate.The specific operation is detailed in Chapter 2 and in Chapter 3.Experimental proof and safety analysis were carried out.Second,a scrambling-based key generation scheme is proposed.Part of the inter-subcarrier symbol interference is reserved as a source of randomness for key generation.The feasibility of the scheme is verified by experiments on a 20-kilometer optical fiber link,and the keys with an inconsistency rate of less than 0.2%and a generation rate of 1.19 Gbit/s are generated.Third,a key generation scheme based on in-band crosstalk is proposed.The key is generated by quantizing symbols affected by in-band crosstalk and channel noise.32QAM and 64QAM,the key generation rates are 1.22 Gbit/s,1.08 Gbit/s and 1.00 Gbit/s,respectively.