# Smart Airport Cybersecurity: Threat Mitigation and Cyber Resilience Controls +
## 5 Smart Airports Attacks: Scenario Development
### Attack Scenarios Analysis Along with Mitigation and Resilience Measures
#### 5.2.2 Malicious Attack: Communication Attack to ATM Systems  
Automatic Dependent Surveillance-Broadcast (ADS-B) is a recently introduced surveillance technology, where aircraft's navigation system determines its position, using a separate global positioning source (GPS), and periodically broadcasts it together with other data, such as aircraft identity and barometric altitude, enabling it to be seen by any adequately equipped agent [25]. The technology has proven particularly attractive in locations, where previously no form of surveillance was physically possible or economically feasible. According to ICAO, ADS-B is now on track to replace conventional radar surveillance systems and become the backbone of next-generation ATM systems [26]. ADS-B avionics broadcast unencrypted, error-code protected messages over radio transmission links, approximately once per second, containing the aircraft's position, velocity, identification, and other ATM-related information [27]. Since ADS-B signals are unauthenticated and unencrypted,  
Figure 7: DDoS attack using Botnets. \"spoofing\" or inserting a fake aircraft into the ADS-B system can be easily accomplished, as shown in Figure 8. Therefore, the system is susceptible to hacking, where attacks may range from passive actions (eavesdropping) to active attacks. The attacks can be implemented using Universal Software Radio Peripheral, a widely available Software-Defined Radio supported by an ADS-B receiver/transmitter chain with GNU Radio [28]. Along with other researchers, [PERSON] has recently published a white paper, presenting active attack scenarios that could result from the weak security posture of satellite communications, revealing how hundreds of in-flight aircrafts are accessible and vulnerable to message jamming, replaying of injection and other active attacks [29]. Impact Evaluation: With open broadcast data and no encryption there is no confidentiality protection for ADS-B communications. Lack of any authentication provides no integrity and the ability to jam signals brings into question availability. As a result, all security parameters may be impacted during such an incident. With air traffic services compromised, only reduced traffic capacity can ensure minimum safety standards. Such an incident happened in September 2017, at Sydney Airport and drove ATM system software failure at Sydney's Air Traffic Control [30]. Cascading effects: The most fundamental security issue with ADS-B is the core idea of broadcasting the identity and precise location of each aircraft, which could open the door for a terrorist to physically attack an aircraft either by using an Unmanned Aerial Vehicle (UAV) to intercept the flight route, or even by using a missile launcher to target aircraft of a specific airline or corporation. This has already happened in the past, like the incident in 2014, with a flight passing over eastern Ukraine, killing all 283 passengers and 15 crew on board [31]. Mitigation Actions: The use of confidentiality and authenticity features in data traffic becomes mandatory. Therefore, cryptographic protection for ADS-B can be an effective mitigation action. It is also important for ground services to have any received data validated, by using legacy surveillance systems, such as primary radar information. Also, in ATM system's dependability is based on redundancies to ensure efficiency, reliability and continuity of operations. Therefore, Air Traffic Control (ATC) has to maintain in use current network of primary and secondary radars, as backup systems to ADS-B advanced technology. In addition, with the use of Wide Area Multilateration technology (WAM), data that show up on a controller's screen are multi-purpose validated by surveillance systems, so that spoofed targets are filtered out [22]. Resilience Measures: It is important to regularly exercise ATC stuff and systems preparedness, response time and provide incident response capabilities. An effective contingency plan should be developed, implemented and tested, so that ATM resilience to be improved.