Διασφάλιση ιδιωτικότητας σε βάσεις δεδομένων σημασιολογικά εμπλουτισμένων τροχιών με έλεγχο ερωτημάτων
Privacy preservation for semantically enriched trajectory databases using query auditing techniques
KeywordsΣύστημα εντοπισμού θέσης
Nowadays, the use of Global Positioning Systems (GPS) has spread so much that they are embedded in many devices. The ease of collecting and storing data from such kind of devices along with the advanced processing capabilities, led to the desire of extracting useful conclusions from them. For example, traffic engineers, environmentalists etc., by analyzing moving entities recorded data, improve the way they work and services provided. Yet, the movement traces in space and time of each recorded entity prove to be a dangerous tool for a malevolent user. Such issues have been largely addressed by the scientific community. In recent years, we have moved from the trajectories on semantically enriched trajectories (semantic trajectories) which provide richer and “deeper” recording / display of a trajectory, leading however to even greater risk of data handed to a malevolent user. This study deals with databases containing semantically-enriched trajectories which remain in-house to the organization that created and maintains them and not with databases whose an anonymous version of the original dataset has been published. Thus, based on relevant approaches regarding “plain” trajectories and quite inspired by earlier work on statistical databases, we, primarily, define our working framework. Subsequently, we identify all potential privacy breaches and recommend a comprehensive query auditing mechanism in order to address these breaches. Finally, as a distinct component of this mechanism, we propose a standalone algorithm (Zoom Out), which helps to improve the user friendliness and functionality of the above mechanism. Its objective is to modify the initial query posed by the user, if it cannot be answered at first for “safety” reasons, to the “nearest” query that can be possibly answered with “safety”.