Secrecy Performance Analysis in Internet of Satellites: Physical Layer Security Perspective

As the latest evolving architecture of space networks, Internet of Satellites (IoSat) is regarded as a promising paradigm in the future beyond 5G and 6G wireless systems. However, due to the extremely large number of satellites and open links, it is challenging to ensure communication security in IoSat, especially for wiretap resisting. To the best of our knowledge, it is an entirely new problem to study the security issue in IoSat, since existing works concerning physical layer security (PLS) in satellite networks mainly focused on the space-to-terrestrial links. It is also noted that, we are the first to investigate PLS problem in IoSat. In light of this, we present in this paper an analytical model of PLS in IoSat where a terrestrial transmitter delivers its information to multi-satellite in the presence of eavesdroppers. By adopting the key parameters such as satellites' deployment density, minimum elevation angle, and orbit height, two major secrecy metric including average secrecy capacity and probability are derived and analyzed. As demonstrated by extensive numerical results, the presented theoretical framework can be utilized to efficiently evaluate the secrecy performance of IoSat, and guide the design and optimization for communication security in such systems.