The Optimization Of Data Reconciliation For CV-QKD Based On TET-LDPC

Quantum secret communication mainly includes two parts: the security key generated by Quantum Key Distribution(QKD)and the "one-time-pad" classic communication.The key used in the "one-time-pad" classic communication is the security key generated by QKD.The "security" here is not absolute security,but relatively secure.No matter what method the key is generated,as long as it is secure and "one-time-pad" communication is realized,then it is a secure communication.Since QKD is applied to quantum unclonability and quantum uncertainty in quantum physics to ensure the security of real-time key transmission,QKD has great research value.The post-processing technology of QKD is the key link of late key extraction.The focus of this paper is to optimize the data reconciliation algorithm in post-processing technology.The main contents of this paper are as follows:1.The basic knowledge of quantum physics used in QKD and the composition structure in QKD systems are introduced.The construction and performance of LowDensity Parity-Check(LDPC)are tested.2.We have constructed a two-edge type low-density parity-check code(TET-LDPC).We introduce a comulative structure similar to that of a repeat-accumulate(RA)code into the TET-LDPC to improve its error correction pergormance.Whereas the reconciliation system achieves higher performance.The simulation results indicate that at a TET-LDPC code rate of 1/2 and a block length of 2×105,the convergence signal-to-noise ratio of the system is reduced to 1.02,the data reconciliation efficiency is 98.58%,the security key rate reaches 17.61 kb/s,and the CV-QKD transmission distance increases to 44.9 km.3.We have proposed Block Adding algorithm that is a construction method of Multiedges type LDPC.The BA construction method can be used to obtain MET-LDPC codes with arbitrary code rates.We can use the degree distribution obtained from density evolution to construct TET-LDPC codes with different code rates and different code lengths.They still show excellent reconciliation performance at high signal-to-noise ratios.According to the simulation results:In the multidimensional reconciliation algorithm,when the bit rate is between 0.6 and 0.8,the reconciliation efficiency is greater than 90%.