Towards secure communication using intra-particle entanglement

TL;DR

This paper investigates using intra-particle entanglement for secure quantum key distribution, highlighting its advantages in local Bell tests and robustness against side channel attacks, with practical implementation via linear optics.

Contribution

It introduces a new intra-particle entanglement-based scheme for device-independent quantum key distribution, enhancing security against specific side channel attacks.

Findings

Intra-particle entanglement allows local Bell tests, decoupling device and channel errors.

The scheme is more secure against side channel attacks than separable state protocols.

Intra-particle entanglement can be generated easily with linear optics.

Abstract

We explore the use of the resource of intra-particle entanglement for secure quantum key distribution in the device-independent scenario. By virtue of the local nature of such entanglement, Bell tests must be implemented locally, which leads to a natural decoupling of device errors from channel errors. We consider a side channel attack on the sender's state preparation device, for which the intra-particle-entanglement based scheme is shown to be more secure than the one that uses separable states. Of practical relevance is the fact that such entanglement can be easily generated using linear optics.