One-sided Device-Independent Quantum Key Distribution: Security, feasibility, and the connection with steering

TL;DR

This paper investigates a practical quantum key distribution protocol where only one party's measurement device is trusted, linking its security to quantum steering and highlighting easier implementation compared to fully device-independent methods.

Contribution

It introduces a one-sided device-independent QKD protocol, demonstrating its security and feasibility, and clarifies its connection to quantum steering, bridging a gap between standard and fully device-independent QKD.

Findings

Security requirements are less stringent than for DI-QKD.

The protocol is more feasible for experimental realization.

Security is linked to demonstrating quantum steering.

Abstract

We analyze the security and feasibility of a protocol for Quantum Key Distribution (QKD), in a context where only one of the two parties trusts his measurement apparatus. This scenario lies naturally between standard QKD, where both parties trust their measurement apparatuses, and Device-Independent QKD (DI-QKD), where neither does, and can be a natural assumption in some practical situations. We show that the requirements for obtaining secure keys are much easier to meet than for DI-QKD, which opens promising experimental opportunities. We clarify the link between the security of this one-sided DI-QKD scenario and the demonstration of quantum steering, in analogy to the link between DI-QKD and the violation of Bell inequalities.