Research On Information Reconciliation And Privacy Amplification Technology In Physical Layer Of Optical Communication

Fiber optic communication is an important solution for achieving long-distance and high-capacity transmission of massive data.However,the emergence of some fiber optic eavesdropping methods also threatens the security of optical fiber communication.As one-time encryption has been proven to effectively protect communication security,many key encryption schemes based on the real-time key distribution are gradually emerging.Therefore,how to ensure the consistency and security of the initial key during the key distribution phase becomes particularly important.During the initial key distribution process,there may be a problem with high key inconsistency rate due to noise and other reasons.At the same time,it’s also possible to monitor the channel during the distribution and information reconciliation stages,resulting in information leakage issues.As the final stage of key distribution,key post processing is precisely the key stage to solve the above problems.Aiming at the above issues,this paper conducts research on information reconciliation and privacy amplification technology in the physical layer of optical communication.The main work is as follows:Firstly,this article proposes an adaptive error correction protocol based on Spinal code.During the use of error correction protocols based on LDPC codes,it was found that their error correction thresholds vary with different bit rates.Therefore,in order to break through the limitation of bit rates on error correction performance,an information reconciliation protocol based on rate free Spinal codes was used.When the KER was not higher than 13%,the reconciliation success rate remained at 90%or above.Secondly,a privacy amplification scheme based on grouped FFT was proposed.The limitation of using MD5,SHA-256,or SHA-512 hash algorithms as privacy amplification algorithms is that their output code length is fixed,and if the input is too short,security cannot be guaranteed.The Toeplitz matrix privacy amplification scheme based on Fast Fourier Transform(FFT)can achieve any input and output length,which consumes a lot of time.Therefore,a privacy amplification scheme based on grouping FFT is adopted.Through simulation verification,the consumption time of the privacy amplification scheme through appropriate grouping is half of the traditional FFT scheme.