Controlled entanglement source for quantum cryptography

TL;DR

This paper introduces a simple, practical method to control entanglement resources in quantum cryptography, enhancing security and usability with minimal additional cost.

Contribution

It proposes a phase randomization protocol to upgrade entanglement sources with access control, addressing resource management and security in quantum cryptography.

Findings

Effective control of entanglement resource achieved

Countermeasure against memory attack demonstrated

Experimental setup with off-the-shelf components implemented

Abstract

Quantum entanglement has become an essential resource in quantum information processing. Existing works employ entangled quantum states to perform various tasks, while little attention is paid to the control of the resource. In this work, we propose a simple protocol to upgrade an entanglement source with access control through phase randomization at the optical pump. The enhanced source can effectively control all users in utilizing the entanglement resource to implement quantum cryptography. In addition, we show this control can act as a practical countermeasure against memory attack on device-independent quantum key distribution at a negligible cost. To demonstrate the feasibility of our protocol, we implement an experimental setup using just off-the-shelf components and characterize its performance accordingly.