Receiver-Device-Independent Quantum Key Distribution Protocols

TL;DR

This paper introduces receiver-device-independent quantum key distribution protocols that are secure against attacks on the receiver's device, even with low channel transmission, by leveraging bounds on state overlaps.

Contribution

It proposes RDI QKD protocols with partial characterization of the sender and black-box receiver, enhancing security against device attacks and practical implementation.

Findings

Protocols remain secure with arbitrarily low channel transmission.

Security is maintained even under blinding attacks on the receiver.

Bounded overlaps enable practical device application.

Abstract

We discuss quantum key distribution protocols and their security analysis, considering a receiver-device-independent (RDI) model. The sender's (Alice's) device is partially characterized, in the sense that we assume bounds on the overlaps of the prepared quantum states. The receiver's (Bob's) device requires no characterisation and can be represented as a black-box. Our protocols are therefore robust to any attack on Bob, such as blinding attacks. In particular, we show that a secret key can be established even when the quantum channel has arbitrarily low transmission by considering RDI protocols exploiting sufficiently many states. Finally, we discuss how the hypothesis of bounded overlaps can be naturally applied to practical devices.