A quantum key distribution protocol for rapid denial of service detection

TL;DR

This paper presents a quantum key distribution protocol that quickly detects fake users attempting to monopolize the connection, maintains high efficiency, and can generate secure keys from two-photon pulses without extra modifications.

Contribution

It introduces a novel QKD protocol that resists denial-of-service attacks and allows secure key generation from two-photon pulses, relaxing BB84 security assumptions.

Findings

Resists denial-of-service attacks effectively

Achieves 100% efficiency above finite key limits

Enables secure key generation from two-photon pulses

Abstract

We introduce a quantum key distribution protocol designed to expose fake users that connect to Alice or Bob for the purpose of monopolising the link and denying service. It inherently resists attempts to exhaust Alice and Bob's initial shared secret, and is 100% efficient, regardless of the number of qubits exchanged above the finite key limit. Additionally, secure key can be generated from two-photon pulses, without having to make any extra modifications. This is made possible by relaxing the security of BB84 to that of the quantum-safe block cipher used for day-to-day encryption, meaning the overall security remains unaffected for useful real-world cryptosystems such as AES-GCM being keyed with quantum devices.