Spread Photon Transceiver for Quantum Secure Communications

Quantum communication protocols provide capabilities for private information exchange despite adversarial access to quantum resources. However, existing protocols can be limited by speed, and considerations around their practical implementation. We report on a novel quantum communications protocol, called the spread photon transceiver, which operates on the physical layer of a communications link with a pair of matched receivers, to achieve quantum security. The sensitivity of the matched receiver architecture to experimental error is evaluated. A security analysis of the protocol is conducted, evaluating the private information rate achievable between the intended sender and receiver, assuming a quantum-powerful adversary, with receiver losses reflective of scenarios which may be encountered in a military field environment.