High performance information reconciliation for QKD with CASCADE

Abstract

It is widely accepted in the quantum cryptography community that interactive information reconciliation protocols, such as cascade, are inefficient due to the communication overhead. Instead, non-interactive information reconciliation protocols based on i.e. LDPC codes or, more recently, polar codes have been proposed. In this work, we argue that interactive protocols should be taken into consideration in modern quantum key distribution systems. In particular, we demonstrate how to improve the performance of cascade by proper implementation and use. Our implementation of cascade reaches a throughput above 80 Mbps under realistic conditions. This is more than twice the throughput previously demonstrated in any information reconciliation protocol.