Efficient Secret Communication Scheme for Bosonic Wiretap Channels Achieves Optimal Secrecy Capacity
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Secure communication remains a critical challenge, and researchers continually seek methods to protect information from eavesdropping. Esther Hänggi, Iyán Méndez Veiga, and Ligong Wang, from Lucerne University of Applied Sciences and Arts and ETH Zurich, now present a novel secret communication scheme designed for the bosonic wiretap channel. This computationally efficient approach utilises standard hardware, such as lasers and photodetectors, and relies on techniques including randomness extractors and pulse-position modulation to ensure security against sophisticated eavesdropping attempts.
The team demonstrates that, under certain conditions, their scheme achieves performance remarkably close to the theoretical limits of secure communication over this channel, representing a significant step towards practical, high-performance quantum cryptography. Measurements on the quantum states it observes are crucial to understanding channel behaviour. In the low-photon-flow limit, the scheme performs optimally and achieves the same dominant term as the established secrecy capacity of the channel.
Bosonic Wiretap Channel, Secure Communication Scheme Scientists developed a novel secure communication scheme for the bosonic wiretap channel, utilizing readily available hardware such as lasers and direct photodetectors. The research centers on a system employing randomness extractors, pulse-position modulation, and Reed-Solomon codes, achieving computational efficiency while maintaining robust security against eavesdroppers attempting to measure the transmitted signals. This scheme operates optimally in the low-photon-flow limit, asymptotically attaining the same dominant term as the established secrecy capacity of the channel. The study modeled the quantum optical communication channel as a pure-loss bosonic wiretap channel, where Alice sends a single-mode optical state to Bob through a beam-splitter, with Eve intercepting the remaining portion. Researchers characterized this channel by defining the relationships between Alice, Bob, Eve, and the environment, assuming Eve does not influence the channel itself. To ensure secure communication, the team limited the average number of photons sent per channel use, rigorously establishing the secrecy capacity of the channel, defining the maximum rate at which Alice can reliably transmit information to Bob while maintaining Eve’s ignorance. The proposed scheme achieves asymptotic capacity in the regime where the number of sent or received photons per channel use approaches zero, demonstrating its effectiveness even under extremely low-signal conditions. This innovative approach represents a significant advancement in secure quantum communication, offering a practical and robust solution for protecting sensitive information. Secure Communication via Bosonic Wiretap Channels Scientists have developed a new secure communication scheme for the bosonic wiretap channel, a model often used to represent quantum optical communication systems. This work achieves a significant breakthrough by utilizing readily available hardware, specifically lasers and direct photodetectors, eliminating the need for complex components. The scheme leverages randomness extractors, pulse-position modulation, and Reed-Solomon codes, resulting in a computationally efficient approach to secure communication. Experiments demonstrate that the proposed scheme achieves asymptotic capacity in the low-photon-flow regime, approaching the theoretical limit of secure communication.
The team established that the scheme’s performance closely matches the established secrecy capacity of the channel. In the limit where the average photon number approaches zero, the secrecy capacity simplifies, demonstrating the scheme’s effectiveness even with extremely weak signals. Crucially, the scheme employs coherent states as the input signals and utilizes direct detection at the receiver, making it highly practical for real-world implementation.
This research confirms a computationally efficient and physically feasible approach to secure communication over quantum channels.
Boson Communication Nears Theoretical Security Limit This research presents a new method for secure communication over channels where signals are transmitted using bosons. The scheme utilizes readily available technology, such as lasers and detectors, and relies on established techniques for data encoding and error correction. Importantly, the method achieves a level of security against eavesdroppers attempting to intercept the communication. In conditions where the flow of light particles is low, the scheme’s performance approaches the theoretical limit for secure communication over this type of channel. Future work will focus on decoupling interdependent parameters through the use of alternative error-correcting codes, reducing the gap between the achievable communication rate and the theoretical capacity, and accounting for imperfections in hardware and environmental noise. These advancements will contribute to more robust and efficient secure communication systems. 👉 More information 🗞 An Efficient Secret Communication Scheme for the Bosonic Wiretap Channel 🧠 ArXiv: https://arxiv.org/abs/2512.08623 Tags: