Secure Communication via a Recycling of Attenuated Classical Signals

Abstract

Combining classical communication with quantum security, while maintaining practical bit rates, has been a goal for many years. The author proposes merging a classical signal with a proven, secure system for quantum key distribution (QKD). The QKD system is based on attenuated reflection of the classical signal, allowing it to securely communicate information while simultaneously building the shared random bits that provide provable security. This system has several advantages over other approaches, including not requiring on-demand single-photon or entangled-state sources.