Improved Asymptotic Key Rate of the B92 Protocol

TL;DR

This paper improves the understanding of the B92 quantum key distribution protocol's security, demonstrating it can securely operate at higher depolarizing rates than previously established, thus enhancing its practical viability.

Contribution

The paper provides a new security analysis of the B92 protocol using Renner’s framework, extending the secure depolarizing rate from 4.2% to 6.5%.

Findings

Secure key generation at 6.5% depolarizing rate

Enhanced security bounds for B92 protocol

Extension beyond previous 4.2% limit

Abstract

We analyze the asymptotic key rate of the single photon B92 protocol by using Renner's security analysis given in 2005. The new analysis shows that the B92 protocol can securely generate key at 6.5% depolarizing rate, while the previous analyses cannot guarantee the secure key generation at 4.2% depolarizing rate.