Information reconciliation for quantum key distribution

摘要: Quantum key distribution (QKD) relies on quantum and classical procedures in orderto achieve the growing of a secret random string --the key-- known only to twoparties executing protocol. Limited intrinsic efficiency protocol, imperfectdevices eavesdropping produce errors information leakage from which set ofmeasured signals raw must be stripped order distill final, informationtheoretically secure, key. The distillation process is one basisreconciliation, error correction privacy amplification protocols are applied rawkey. This cleaning as reconciliation done afast efficient way avoid cramping performance QKD system. Brassardand Salvail proposed very simple elegant protocol reconcile keys secret-key agreement context, Cascade, that has become de-facto standard for allQKD practical implementations. However, it highly interactive, requiring many com-munications between legitimate parties its not optimal, imposing anearly limit maximum tolerable rate. In this paper we describe low-densityparity-check improves significantly these problems. Theprotocol exhibits better limits number uses communicationschannel. It also able adapt different rates while remaining efficient, thusreaching longer distances or higher secure rate given