Private information via the Unruh effect

TL;DR

This paper explores how the Unruh effect creates a natural noise that can be exploited to achieve perfect quantum communication security against an accelerated eavesdropper in relativistic quantum information scenarios.

Contribution

It demonstrates that the private quantum capacity equals the entanglement-assisted quantum capacity for the eavesdropper's channel, providing a new security mechanism in relativistic quantum communication.

Findings

Private quantum capacity equals entanglement-assisted quantum capacity.

Security improves with the eavesdropper's acceleration.

The capacity is evaluated for all accelerations.

Abstract

In a relativistic theory of quantum information, the possible presence of horizons is a complicating feature placing restrictions on the transmission and retrieval of information. We consider two inertial participants communicating via a noiseless qubit channel in the presence of a uniformly accelerated eavesdropper. Owing to the Unruh effect, the eavesdropper's view of any encoded information is noisy, a feature the two inertial participants can exploit to achieve perfectly secure quantum communication. We show that the associated private quantum capacity is equal to the entanglement-assisted quantum capacity for the channel to the eavesdropper's environment, which we evaluate for all accelerations.