FET: Small: Quantum-secure quantum-enhanced covert networks over generalized bosonic channels

University Of Arizona, Tucson AZ

Investigators

Abstract

Security and privacy are of utmost importance to communications, with standard cryptography-based approaches well studied in the literature. However, these approaches are limited to protecting the content of transmissions, which is insufficient when the detection of the transmission must be prevented in the first place. Covert, or low probability of detection/intercept (LPD/LPI) communication is thus necessary in many settings, including military operations. At the same time, quantum methodology has been demonstrated to benefit substantially the performance of non-covert communications. This project focuses on quantifying the fundamental improvements to security and throughput of covert communication networks offered by quantum information processing, as well as characterizing the systems for achieving these gains. Additionally, the research team mentors graduate and undergraduate students involved in this project, and engages in collaborative efforts to validate the results experimentally. Covert communication has thus far been studied largely from the classical viewpoint. This includes both the practical approaches to system design such as spread spectrum as well as the corresponding information-theoretic limits. However, quantum, not classical, mechanics govern the fundamental laws of physics. Leveraging quantum methodology has yielded encryption systems that are provably secure against the adversary restricted only by the laws of physics. Quantum phenomena such as entanglement have been shown to substantially improve the non-covert communication bitrate. This project takes the quantum perspective to covertness. It looks to determine the fundamental limits of covert communication in a networked setting that is secure against the adversary who is only subject to the laws of physics. This assumption yields mathematically provable covertness against the most powerful adversary possible. These limits are sought for communication under different channel conditions (including dynamic links due to platform mobility and time-varying channel conditions) and resources available to the communicating parties (including quantum processing of light). Furthermore, transmitter and receiver structures and algorithms are being devised to achieve these limits. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.