面向空间信息网络的隐蔽通信技术综述
摘要
Space information network (SIN) is a space-air-ground-integrated network, which consists of spacecraft, aircraft and ground communication facilities deployed in different orbits and performing different missions. The SIN has several characteristics such as extremely large scale, multi-layer topology, open communication environment and supporting various services. Through networking and connection between satellites, aerial nodes and terrestrial nodes, it can achieve seamless global communications efficiently. On the other hand, the SIN is open to the wireless environment without physical isolation. Although this can benefit information dissemination, the information is also easy to be leaked. Therefore, the SIN is facing great security challenges. Covert communication is an important technology for secure transmission. When the information is transmitted to the receiver, it can guarantee that the detection probability of the illegal warden is small enough, and thus the transmission can be hidden. Through using covert communication technology, the transmission reliability and security for SIN can be preserved. In this paper, the covert communications of SIN are surveyed. Specifically, the research works and recent progress of covert communications in SIN are introduced from the aspects of background introduction, key techniques, application scenarios and future challenges.