## 2 Overview of Cyber Threats in EM
### Communication Media
#### 2.1.5 Satellite Communications  
Satellite radio [74], hybrid terrestrial-satellite mobile networks [75] and other satellite network systems have been proposed and some are routinely used for disaster recovery [76]. An example such system that combines satellite and mobile phone technologies is used in South Africa as an emergency alert system [15]. CISCO's hastily-formed network (HFN) approach for emergency response and disaster relief also relies heavily on satellite Internet when the terrestrial infrastructure is degraded or destroyed. While costly and slow, it can be rapidly deployed and may be the only available option in a disaster environment [77]. Common types of portable satellite systems are VSAT (Very Small Aperture Terminal) and BGAN (Broadband Global Area Network). They need to have clear line of sight to the provider's satellites and provide speeds from 128 kbps to 30 Mbps, but typically at the lower end [32,77]. Satellite communication is generally unreliable. Service can be temporarily degraded due to too many terminals in one area or due to a storm over the end-user's ground terminal or the provider's earth station [77]. Although not strictly a security measure, quality of service algorithms can prove useful by compensating for the high latency and jitter experienced by satellite voice and video communication end-users [77]. The availability of satellite communication has traditionally been a significant concern, especially in the defence sector. For this reason, several anti-jamming technologies have been employed on military satellites. These may include Spread Spectrum, EHF frequencies, directional antenna beams and signal processing techniques for jamming mitigation, which are typically not used by commercial satellites [55] employed in EM. As the technologies exist though, this is related to commercial decisions rather than a technical research issue. However, satellite communication availability can also be disrupted via cyber means, such as a network denial of service attack. We describe the related open issue for research next. _Open issues in security of Satellite Communications used in EM_: Due to its low capacity and its role as the Internet gateway at locations where there is no other direct Internet access, the satellite link is often a bottleneck on which local wireless networks have to depend. As a result, denial of service on the satellite link, whether accidental or intentional, is a major concern. One of the very few security breaches documented to have affected an actual emergency response operation was a denial of service attack on the satellite link used by CISCO at the 2008 Evans Road Fire emergency in North Carolina. A fire-fighter's laptop that had been previously infected by trojan software started scanning as soon as it connected to the operation's HFN and launched a denial of service attack through the satellite link, which was quickly overwhelmed. Since then, CISCO has implemented egress filtering at each component network that is connected to the satellite and has introduced policies for authentication of users and regulated use of the link [32]. This reduces the likelihood of accidental denial of service incidents, but it is unclear whether it would provide protection against intentional ones or availability attacks that are not based on flooding. This remains an open issue for research in EM satellite communications. In addition, the security of confidentiality of communications using satellite phones has been contested by researchers. [PERSON] _et al_. [31] have recently reverse-engineered the encryption algorithms used in the GMR-1 and GMR-2 satellite phone standards and showed that their stream ciphers are considerably weaker than the current state of the art in symmetric cryptography. They have also developed a mechanism for recovering the encryption key of a GMR-2 phone call with approximately 50-65 bytes of key stream and moderate computational complexity.