# A Survey on Satellite Communication System Security
## 1 Introduction  
The Internet of Everything (IoE), which aims to connect all devices and systems in every possible location, has become the next dominant objective of communication. However, traditional land-based communication systems (e.g., cellular communication) are unable to cover the vast distances required for such connections. For instance, agriculture management with smart devices in the US requires vast coverage because of its land area, which existing telecommunications cannot cover. In response, satellite communication systems (SCSs) have become a popular alternative due to their wide coverage. Although SCSs have an advantage with respect to coverage, in the early days, the use of SCSs was restricted to military and scientific applications, such as surveillance and weather forecasting [1], due to the high costs associated with the technical advancement of satellite launches and communication between satellites. However, with the advancement of both technologies, as exemplified by SpaceX [2, 3] and Radio Frequency (RF)-based communication, SCSs have evolved significantly in recent years. Rapid development has resulted in various consequences. One is user experience enhancement. For instance, companies like OneWeb and Amazon Kuiper provide low-latency and wide-coverage communication by integrating mega-constellation low Earth orbit (LEO) SCSs with ground communications (through gateways or direct communication with a terminal). This technology enables communication in places where ground communication alone is inadequate, such as aircraft, ships, and rural areas, and provides users with asimilar communication experience as in cities (Figure 1). Another is enhancing the performance of existing technology. For example, in the past, the global positioning system (GPS) created by the United States was the only option available. Nowadays, consumers can access more precise time and position data through various ground navigation satellite systems (GNSSs) powered by SCSs, such as GLONASS, Galileo, and Beidou, developed by countries or alliances (Figure 1). However, the extensive development and deployment of SCSs have not come without challenges. Cyber attacks on SCSs have increased due to the exploitation of vulnerabilities that stem from their environmental and technical limitations. For example, military drone traffic information during the Iraq War, communicated via an SCS, was eavesdropped due to the lack of encryption caused by the limited communication bandwidth (compared to terrestrial communication) of the SCS [4]. Also, in 2011, Iran conducted a GPS spoofing attack on a U.S.-built RQ-170 Sentinel that misled a UAV into landing in Iran by feeding it false GPS information, making it perceive Iran as its home base in Afghanistan. This is because the significant distance between Earth and satellites results in communication delays, fostering latency and increasing the susceptibility of SCSs to spoofing threats. In addition to attacks on dedicated SCSs, cyber attacks on the latest SCS for general communication are also prevalent. For example, during the early stages of the Russia-Ukraine war, the deployment of the AcidRain [5] malware targeted Ukraine's KA-SAT satellite broadband service, causing widespread disruption by wiping data for thousands of SCS modems across Ukraine and Europe. This attack not only rendered the modems inoperative but its impact also extended to the remote monitoring or control of thousands of wind turbines. Following this, a new variant of the malware, named AcidPour, was discovered, demonstrating an evolution in the cyber threat landscape targeting satellite communication systems. The progression from AcidRain to AcidPour highlights cyber threats to satellite  
Figure 1: Satellite communication system scheme. communications, underscoring the requirement for robust defense mechanisms to protect these critical infrastructure components from such destructive attacks.