An architecture and protocol, an access control model, and a sighting blurring algorithm for improving users' security in the context of location based services operating over the internet

摘要

A new type of service, known as a Location Based Service (LBS), is emerging thatudincorporates users' location information, and many of these LBSs operate over theudInternet. However, the potential misuse of this location information is a seriousudconcern. Therefore, the main goal of this thesis is to develop techniques, whichudincrease users' security and privacy, for use with these LBSs.udThe rst technique that we propose is a three-party protocol that is used to mutuallyudidentify and authenticate users, LBSs, and a trusted middleware infrastructureudthat is responsible for managing the users' identity and location information. Thisudprotocol enables users to simultaneously identify and authenticate themselves to theudinfrastructure using real identities, and to the LBSs using pseudonyms. This protocoludcan be subsequently used to securely exchange messages containing locationudinformation.udThe second technique that we propose is an access control model that enablesudusers to create permissions that specify which users and LBSs are entitled to obtainudlocation information about which other users, under what circumstances the locationudinformation is released to the users and LBSs, and the accuracy of any locationudinformation that is released to the users and LBSs.udThe third technique that we propose is a blurring algorithm that performs spatialudblurring on users' location information. It does not perform temporal blurring,udbecause this reduces an LBS's ability to offer a useful service. Instead, our blurringudalgorithm introduces a new parameter that species the frequency with which locationudinformation is released for a particular user. This frequency parameter is audfunction of the size of the blurred location.udThese three techniques can be used as part of an overall solution for providingudusers with increased security while using LBSs that operate over the Internet.