Detection loophole attacks on semi-device-independent quantum and classical protocols

TL;DR

This paper investigates how detection inefficiencies can be exploited in semi-device-independent quantum and classical protocols, potentially compromising their security, and discusses methods to prevent such attacks.

Contribution

It identifies specific conditions where detection loopholes can be exploited and proposes strategies to secure semi-device-independent protocols against these attacks.

Findings

Detection loopholes can be exploited by malicious providers.

Conditions for successful attacks are characterized.

Strategies to prevent such attacks are discussed.

Abstract

Semi-device-independent quantum protocols realize information tasks - e.g. secure key distribution, random access coding, and randomness generation - in a scenario where no assumption on the internal working of the devices used in the protocol is made, except their dimension. These protocols offer two main advantages: first, their implementation is often less demanding than fully-device-independent protocols. Second, they are more secure than their device-dependent counterparts. Their classical analogous is represented by random access codes, which provide a general framework for describing one-sided classical communication tasks. We discuss conditions under which detection inefficiencies can be exploited by a malicious provider to fake the performance of semi-device-independent quantum and classical protocols - and how to prevent it.