I. Introduction
Terrorism has threatened the freedom to travel throughout the history of commercial aviation [1]. In the last few years, there is an increasing number of serious air disasters around the world, many of which have been confirmed or suspected to be associated with terrorist attacks. Generally, in-depth screening and physical inspection can effectively identify or deter potential threats, and thus reduce the risk of being attacked. However, doing so on every passenger may be very costly and create delays and complaints, decreasing the welfare of the approver (airports and airlines) [2]. A tradeoff is to use passenger profiling to identify potential attackers who constitute only a very small fraction of passengers: if profiling can correctly identify likely attackers and likely normal passengers, in-depth screening and inspection efforts can be better tailored to target the likely attackers. Such a mechanism has been used in aviation security management for a long time in order to reduce the inconvenience caused to normal passengers and the overall cost of security in transportation systems [3].