Survey of Satellite Covert Communications: Status, Key Technologies, and Future Challenges

DENG Hao; SUN Weiyuan; ZHU Zhengyu; PAN Gaofeng; SUN Gangcan

doi:10.11999/JEIT260177

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DENG Hao, SUN Weiyuan, ZHU Zhengyu, PAN Gaofeng, SUN Gangcan. Survey of Satellite Covert Communications: Status, Key Technologies, and Future Challenges[J]. Journal of Electronics & Information Technology. doi: 10.11999/JEIT260177

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DENG Hao, SUN Weiyuan, ZHU Zhengyu, PAN Gaofeng, SUN Gangcan. Survey of Satellite Covert Communications: Status, Key Technologies, and Future Challenges[J]. Journal of Electronics & Information Technology. doi: 10.11999/JEIT260177

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Survey of Satellite Covert Communications: Status, Key Technologies, and Future Challenges

doi: 10.11999/JEIT260177 cstr: 32379.14.JEIT260177

1.
School of Physics and Electronics, Henan University, Kaifeng 475004, China
2.
School of Future Technology, Henan University, Zhengzhou 450046, China
3.
School of Electrical and Information Engineering, Zhengzhou University, Zhengzhou 450001, China
4.
School of Cyberspace Science and Technology, Beijing Institute of Technology, Beijing 100081, China

Funds: The National Natural Science Foundation of China (62571495, 62571182), The State Key Laboratory of Networking and Switching Technology(Beijing University of Posts and Telecommunications) (SKLNST-2025-1-07), The Science Foundation of Henan Province (232300421097), The for Science & Technology Innovation Talents in Universities of Henan Province (23HASTIT019)

Received Date: 2026-02-09
Accepted Date: 2026-07-06
Rev Recd Date: 2026-07-06

Available Online: 2026-07-19

Abstract

Abstract

Objective This survey systematically reviews the theoretical foundations, key technologies, and future challenges of Satellite Covert Communications. Based on the classical Alice-Bob-Willie model, the effects of satellite channel characteristics on covert communication capacity are analyzed to establish the theoretical basis. The network architecture of Satellite Covert Communications under the space-air-ground three-layer framework (Fig. 1) is summarized. Core technologies and optimization methods, including signal camouflage coding, beamforming, spectrum agility, Quantum Key Distribution (QKD), and Artificial Intelligence (AI)-assisted techniques, are systematically reviewed. Major security threats and corresponding multi-layer defense strategies, including Physical-Layer Security (PLS) and intelligent collaborative defense, are also summarized. This survey provides a theoretical foundation and technical guidance for developing highly secure and intelligent Satellite Covert Communications systems. Significance The significance of this survey lies in its systematic integration of the theoretical framework and key technologies for Satellite Covert Communications. To address the threats of detection, interference, and eavesdropping in open satellite communication environments, representative space-air-ground integrated architectures reported in the literature are reviewed. These architectures overcome the limitation of conventional encryption techniques, which protect only information content, by reducing statistical distinguishability at the physical layer to achieve a low probability of detection. The constraints imposed by satellite channels on covert communication capacity are clarified through the modified Square Root Law. Enhancement strategies based on adaptive coding, beamforming, spectrum agility, and related techniques are reviewed to establish a comprehensive technical framework for Satellite Covert Communications. These advances provide theoretical support and technical guidance for constructing highly survivable and secure space-air-ground integrated communication networks, with important applications in national defense, emergency communications, and Sixth-Generation (6G) Non-Terrestrial Networks (NTNs). Progress Existing studies demonstrate that Doppler spread has a dual effect on covert communication capacity. It increases the missed detection probability while introducing signal distortion, making adaptive coding necessary to maintain reliable transmission. The differences in detection capability among terrestrial, aerial, and orbital wardens (Willie) are quantified (Table 1), providing a theoretical basis for hierarchical defense design. Existing studies have also proposed multi-level covertness enhancement strategies. AI-assisted dynamic camouflage combined with sparse coding exploits background noise, inter-satellite links, and dynamic beamforming to improve covert throughput. At the network level, cooperative Unmanned Aerial Vehicle (UAV)-assisted transmission and dynamic spectrum coordination are identified as representative enhancement approaches (Fig. 3). Furthermore, a hierarchical defense framework is summarized from representative studies. This framework combines Reconfigurable Intelligent Surface (RIS)-assisted signal control, Stackelberg game-based incentives for cooperative jamming, XOR network coding, and federated learning for cross-domain threat feature sharing. These advances provide effective solutions for improving the covertness and security of Satellite Covert Communications. Conclusions This survey systematically reviews the theoretical foundations and recent advances in Satellite Covert Communications. The integration of multi-layer satellite constellations, dynamic aerial relay platforms, and software-defined networks supported by Quantum Key Distribution (QKD) enables resilient global covert communication. Extending the Alice-Bob-Willie model to practical satellite channels with non-ideal propagation characteristics provides guidance for covert throughput optimization and secure transmission. AI-assisted coding and waveform design further enable adaptive transmission strategies that respond to dynamic channel conditions. Future research should focus on robust covert transmission in dynamic Low Earth Orbit (LEO) environments, scalable constellation management, and the deep integration of AI and quantum technologies into 6G NTNs. The convergence of programmable satellites, Reconfigurable Intelligent Surfaces (RIS), and advanced machine learning is expected to further improve secure space communications. Prospects Future research should focus on four major directions: robust covert transmission under non-ideal channels, AI-assisted intelligent decision-making, integrated 6G NTN networking, and the integration of quantum communication technologies (Fig. 4). High-precision Doppler compensation techniques should be developed to mitigate rapid channel variations in LEO satellite systems. Robust covert transmission schemes should also be developed for imperfect Channel State Information (CSI), with deep reinforcement learning providing real-time resource optimization. Future studies should strengthen the integration of AI and quantum technologies by combining cross-layer QKD with covert transmission protocols and exploiting Software-Defined Satellite (SDS) capabilities for adaptive strategy deployment. Additional opportunities include using RIS to enhance spatial-domain signal control and applying blockchain technology to address trust management in multi-node cooperative networks. Efficient lightweight onboard algorithms and coordinated international frameworks for spectrum and orbital resource management should also be developed to support future Satellite Covert Communications systems.
- Satellite covert communications,
- Signal camouflage coding,
- Beamforming,
- Spectrum agility

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References(52)

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