Preserving mobile customer privacy: An access control system for moving objects and customer profiles

A key challenge for Mobile services is to offer personalized contents while preserving the privacy of customers. In mobile applications, location information is modeled as moving objects. Providing proper protection to customer information can be achieved by an access control system. However, providing such system is a challenging task due to: 1) the spatio-temporal nature of the constraints as well as the location information, and the interaction among them; 2) the complexity of resolving spatiotemporal and granularity conflicts; and 3) the required scalability and efficiency. In this paper, we present a solution that includes an access control model for moving objects and customer profiles. We also present a mechanism that enforces the spatio-temporal policies. The mechanism consists of three components: a text encoder, a spatio-temporal module that computes interactions between moving objects and spatio-temporal constraints, and a new data structure referred to as the Adaptive Search Multi-way trie (ASM-trie). We present the insertion and search algorithms of the ASM-trie and an evaluation study that shows the positive impact of the ASM-trie on the search efficiency.