Fair Efficiency Comparisons of Decoy‐State Quantum Key Distribution Protocols

Abstract

Taking the schemes based on different formulas of secure key rate as examples, we give a fair comparison between typical protocols under Universal composable (UC) security frame. Through analyzing the relationship of security parameters in post-processing stage and final secure key rate, we achieve the unified quantification between protocols based on Gottesman-Lo-Lutkenhaus-Preskill (GLLP) formula and the ones under UC security. Based on the above research, the impact of different sending lengths and secure parameters on secure key rate is investigated. Besides, we analyze the conditions of fair comparison, and for the first time we give a fair comparison between the protocols based on GLLP formula and smooth entropy. By typical efficiency comparisons, we summarize the way for improving secure key rate in the light intensity choice and the single bit error rate estimation method.