Symbol-Oriented Quantum Communication via Temporal-Mode Multiplexing

Abstract:We introduce and analyze a quantum-assisted classical communication protocol that encodes symbols from a finite alphabet onto temporal modes using the LM05 operation as a building block. The protocol applies a bit-flip gate independently to temporal slots corresponding to message symbols, yielding a tensor product of LM05 operations on parallel channels. This tensor product structure enables collective attacks not covered by standard LM05 security proofs. We derive a theoretical upper bound on the success probability for complete recovery under random guessing, accounting for the receiver's 50\% guessing ability on lost photons, and emphasize that this bound assumes perfect loss identification. We characterize the intended transmission, derive an asymptotic collective-attack bound for the symbol-set mode, and identify open challenges for composable security. The protocol is not a standalone Quantum Secure Direct Communication scheme, as the classical ordering information requires encryption. For a 53-symbol alphabet, the optimistic 1\% success bound occurs at about 0.8 kilometers under zero QBER and reduces to about 0.6 kilometers for QBER equals 0.01; practical constraints severely limit performance.

arXiv:2608.05038 [quant-ph]

(or arXiv:2608.05038v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2608.05038 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.

Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.

Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.