An Efficient Secret Communication Scheme for the Bosonic Wiretap Channel

TL;DR

This paper introduces a computationally efficient secret communication scheme for the bosonic wiretap channel, utilizing practical hardware and advanced coding techniques to ensure security against quantum eavesdroppers, especially effective in low-photon scenarios.

Contribution

It presents a novel secret communication scheme combining randomness extractors, pulse-position modulation, and Reed-Solomon codes tailored for the bosonic wiretap channel, achieving asymptotic optimality.

Findings

Scheme is secure against coherent joint measurements by eavesdroppers.

Achieves the same dominant term as the secrecy capacity in low-photon limit.

Utilizes readily available hardware for practical implementation.

Abstract

We propose a new secret communication scheme over the bosonic wiretap channel. It uses readily available hardware such as lasers and direct photodetectors. The scheme is based on randomness extractors, pulse-position modulation, and Reed-Solomon codes and is therefore computationally efficient. It is secure against an eavesdropper performing coherent joint measurements on the quantum states it observes. In the low-photon-flow limit, the scheme is asymptotically optimal and achieves the same dominant term as the secrecy capacity of the same channel.