# AIS Data Vulnerability Indicated by a Spoofing Case-Study
## 1 Introduction  
Maritime industry stakeholders built the AIS with the goal of improving maritime safety, security, and MSA. The AIS was launched as a joint effort of the International Maritime Organization (IMO), the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA), the International Telecommunication Union (ITU), and the International Electrotechnical Commission (IEC) [1]. The IMO provides carriage requirements and performance standards. The IALA provides basic technical requirements, while the ITU and the IEC provide the broadcasting and electrotechnical standards of AIS. Although the development and deployment of AIS has contributed significantly to increased navigational safety, it has also resulted in numerous safety and security issues. Originally, AIS was introduced on certain types of International Convention for Safety of Life at Sea (SOLAS) ships to assist the Officer of the Watch (OOW) in making decisions in the event of a collision. AIS provides the OOW with the most accurate and detailed data on all detected targets. This is very important for the OOW, especially targets that are at risk of or dangerously close to collision [2]. In addition, the data from AIS can be integrated into the Automatic Radar Plotting Aid (ARPA) and chart systems (Electronic Chart Display and Information System (ECDIS) or Electronic Chart Systems (ECS)) [2,3]. This provides the OOW with an additional source of navigation data (e.g., Closest Point of Approach (CPA)) that can help the OOW navigate or mislead him when the AIS station is spoofed. Although the use of AIS on ships has increased the safety of navigation, it is important to emphasize that AIS is not intended to guide navigation but to exchange navigational and other relevant data between ships and shore stations [4]. According to SOLAS regulation V/19.2.4, all ships of 300 gross tonnage (GT) and more engaged in international voyages and cargo ships of 500 GT and more not engagedin international voyages, as well as passenger ships, irrespective of their size, shall be equipped with AIS [5]. Behind these international regulations, the European Union and national authorities have also developed obligations regarding AIS for non-SOLAS ships (i.e., fishing and pleasure boats). To date, various AIS stations have been developed. According to IALA guideline 1082, AIS stations can be grouped by class and function into mobile and fixed stations with corresponding types of AIS. Mobile AIS stations are grouped by class into shipborne class A and B stations, AIS SART, MOB-AIS, EPIIRB-AIS and AIS and SAR aircraft, while fixed AIS stations are AIS base stations (AIS BS), AIS repeaters, and AIS aids to navigation (AtoN) [1]. Figure 1 shows the classification of AIS stations. Satellite-based AIS (S-AIS) have been introduced [7; 8], and further development will include AIS used in the IMO e-navigation concept [6]. With the introduction of S-AIS, the coverage area of AIS has been extended from the very high frequency (VHF) range up to 400 km [9]. Although some countries already use AIS data from national satellites to monitor vessel traffic in sea areas off the national coast, global coverage of sea areas with S-AIS has not yet been established [7; 8; 10]. The wide use of this system and its advantages in the commercial sector will be recognized in the near future [11]. National authorities will be able to receive AIS signals from ships in the maritime zone under their jurisdiction directly from the AIS satellite service. In addition, data from S-AIS have a variety of regional and global applications as well as maritime spatial planning [8; 12]. The transponders of AIS transmit and receive specific information on dedicated VHF frequencies [13]. The AIS automatically transmits and receives this information from similarly equipped ships, monitors and tracks ships, and exchanges data with land-based facilities [5].