Optimized Algorithm For Data Reconciliation Based On Continuous Variable Quantum Key Distribution

With the gradual improvement of quantum theory, quantum cryptography from theory to reality. Data reconciliation is one of the most critical of quantum key distribution. In the communication process, the sender Alice transfer quantum state information to the receiver Bob via fiber. Because of the channel noise and the possible presence of eavesdropping of the third part Eve, the continuous variable quantum signal which Bob received is different from Alice’s send and appears error codes. Data reconciliation is accomplished by selecting an error correction scheme and channel coding algorithm, which makes the sender and the receiver get the same sequence.We choose low complexity and high performance LDPC code as error correcting codes. On the basis of the simulation results EXIT chart analysis, established the Gaussian approximation algorithm based on PSO of continuous variable quantum key distribution data reconciliation. At the same time, we pick out the best distribution based on the future of EXIT chart and Applied to the data reconciliation of continuous variables coherent states based quantum key distribution. The simulation results of the algorithm written by C language show that the reliable data reconciliation can be realized when the SNR of quantum channel is above 4.9dB and the number of packets of continuous variables is 2×105.