Detection of malicious AIS position spoofing by exploiting radar information

The Automatic Identification System (AIS) is an automatic tracking system based on reports provided by the vessels carrying an AIS transponder. The reports contain information on the vessel position, velocity etc. and typically have high accuracy. Given that the AIS is a self-reporting system, the trustworthiness of positional information depends on data being reported by the vessel, rather than measured by a sensor. Any self-reporting system is prone to “spoofing” or the intentional reporting on incorrect information. This paper addresses the inference problem of whether the received AIS data are trustworthy with the help of radar measurements and information from the tracking system. This problem can be treated in the hypothesis testing framework where the null hypothesis is that the AIS data are trustworthy and the alternative hypothesis is that the data are spoofed. The proposed solution, the generalized version of the sequential log-likelihood ratio test, is compared to the ideally optimal solution using real and simulated data.