A Privacy-Preserving Pay-by-Phone Parking System

Most cities around the world require drivers to pay for the time they occupy a parking spot. In this way, drivers are encouraged to shorten the parking time so that other drivers are given a reasonable chance of finding parking. The traditional way, based on moving to a pay station and placing the issued parking ticket on the dashboard of the car, presents several drawbacks, such as having to predict in advance the duration of parking or the need to move to the car in case the parking time has to be extended. Over the past few years, several applications permitting payment through mobile phones have appeared. Such applications manage detailed information about parking operations so that accurate profiles of parking habits of car owners can be created. In this paper, we propose a system to pay for parking by phone that preserves the privacy of drivers. The information managed by the system is proven not to provide any help to the creation of profiles of parking habits. An attacker with full access to all this information can not do better than he or she would do by patrolling the city for collecting information about parked cars.