Secure electronic monitoring of sex offenders

Electronic monitoring is a viable approach to controlling sex offenders and making the environment safe for victims. Two technologies are currently being adopted: RFID and GPS. Both technologies aim to detect the proximity between the offender and the victim and alert the relevant authorities in real time. However, the security of the system adopted is a key issue, given the risk to the victim’s safety. In this paper, we analyze the existing approaches from the perspective of security, in case of possible misbehavior of the offender. The theoretical analysis shows that GPS is the best choice when high security requirements are desired. In fact, radio frequency attacks are possible for RFID, endangering the victim. However, when GPS is adopted, privacy issues become critical. In particular, when considering a victim moving around the territory, it is unacceptable to track them even with the goal of offering protection. To overcome this drawback, we propose a GPS-based solution that does not allow the victim’s location to be revealed unless the offender is nearby, thus finding a solution that advances the state of the art.