# A Survey on Satellite Communication System Security
## 4 Attacks in Satellite Communication Systems
### Confidentiality Threats  
Eavesdropping entails the secretive act of intercepting and listening to private conversations, electronic communications, or transmissions between individuals without their knowledge or consent, often using sophisticated devices or techniques to breach confidentiality. This type of attack is traditionally associated with overhearing conversations without being detected, but in the modern context, it extends to various forms of electronic and digital surveillance [31]. An eavesdropping attack in SCSs is a type of security breach where an unauthorized party intercepts and listens to the communication transmitted via a satellite network. This has become possible due to the characteristics of satellites, such as wireless communication, wide coverage, and unencrypted communications resulting from a low bandwidth. Also, this kind of attack can be particularly concerning due to the broad coverage and diverse use of SCSs, ranging from personal communication to critical military and government transmissions. The attack involves equipment to intercept the satellite signal ranging from a simple setup for unencrypted signals to more complex systems capable of breaking encryption. In this section, we approach eavesdropping attacks by dividing them into passive eavesdropping and active eavesdropping. Additionally, the overall process of the two attacks is depicted in Figure 5 and a comparison of the two attacks is presented in Table 3.  
Figure 4: Attack schemes in satellite communication systems. Figure 5: Eavesdropping attack scheme. **Passive Eavesdropping:** Passive eavesdropping is listening to or recording communication without altering or interacting with the transmission. The eavesdropper is essentially a silent observer. This type of attack can be difficult for the victim to detect, but it may also be challenging for the attacker to obtain meaningful information. The authors of [32] introduced RECORD, a novel passive attack method targeting LEO satellite users which compromises their location privacy by exploiting the downlink from wandering communication satellites. This method, implemented on a custom satellite reception platform, uses real-world data from the Iridium SCS to demonstrate that observing just 2.3 h of traffic can significantly narrow down a user's position to less than an 11 km radius, a drastic reduction from the initial 4700 km satellite beam diameter. Also, [33] presents a detailed experimental security analysis of satellite broadband signals using the Digital Video Broadcasting for Satellite (DVB-S) protocol, highlighting vulnerabilities that allow for the identification of individual satellite customers and their activities, as well as posing threats to critical infrastructure. This research uncovers various network topologies prone to interception, revealing a substantial amount of sensitive data, including Secure Sockets Layer (SSL) and Transport Layer Security (TLS) certificates, unencrypted HyperText Transfer Protocol (HTTP) requests, emails, and Voice Over Internet Protocol (VoIP) conversations. This data exposure raises severe risks to critical infrastructure, especially in power generation facilities where unencrypted communications were detected. **Active Eavesdropping:** Active eavesdropping involves a certain level of intervention in communication. It is an attack where the eavesdropper decrypts encrypted signals or intervenes in the communication process to directly intercept the data. While this form of attack increases the risk of detection, it also requires the collection of more effective information. [PERSON] et al. [34] introduced a breakthrough in decrypting communications within the Thuraya satellite network, which uses the GEO-Mobile Radio(GMR)-1 standard. By enhancing a ciphertext-only attack and leveraging open-source software, the authors successfully decrypted their own communications, showcasing vulnerabilities in the GMR-1 and GMR-2 SCS standards.