Privacy Preserved Model Based Approaches for Generating Open Travel Behavioural Data

Location-aware technologies and smart phones are fast growing in usage and adoption as a medium of service request and delivery of daily activities. However, the increasing usage of these technologies has birthed new challenges that needs to be addressed. Privacy protection and the need for disaggregate mobility data for transportation modelling needs to be balanced for applications and academic research. This dissertation focuses on developing modern privacy mechanisms that seek to satisfy requirements on privacy and data utility for fine-grained travel behavioural modelling applications using large-scale mobility data. To accomplish this, we review the challenges and opportunities that are needed to be solved in order to harness the full potential of “Big Transportation Data”. Also, we perform a quantitative evaluation on the degree of privacy that are provided by popular location anonymization techniques when undertaken on sensitive location data (i.e. homes, offices) of a travel survey. As a step to solve the trade-off between privacy and utility, we develop a differentially-private generative model for simultaneously synthesizing both socio-economic attributes and sequences of activity diary. Adversarial attack models are proposed and tested to evaluate the effectiveness of the proposed system against privacy attacks. The results show that datasets from the developed privacy enhancing system can be used for travel behavioural modelling with satisfactory results while ensuring an acceptable level of privacy

Sensor Network-based and User-friendly User Location Discovery for Future Smart Homes

User location is crucial context information for future smart homes where a lot of location based services will be proposed. This location necessarily means that User Location Discovery (ULD) will play an important role in future smart homes. Concerns about privacy and the need to carry a mobile or a tag device within a smart home currently makes conventional ULD systems uncomfortable for users. Future smart homes will need a ULD system to consider these challenges. This paper addresses to design such a ULD system for context-aware services in future smart homes stressing on the following challenges: (i) users’ privacy, (ii) device/tag-free, and (iii) fault tolerance and accuracy. On the other hand, emerging new technologies such as Internet of Things, embedded systems, intelligent devices and machine-to-machine communication are penetrating into our daily life with more and more sensors available for use in our homes. Considering this opportunity, we propose a ULD system that is capitalizing on the prevalence of sensors or home while satisfying the aforementioned challenges. The proposed sensor network-based and user-friendly ULD system relies on different types of cheap sensors as well as a context broker with a fuzzy-based decision maker. The context broker receives context information from different types of sensors and evaluates that data using the fuzzy set theory. We demonstrate the performance of the proposed system by illustrating a use case, utilizing both an analytical model and simulation

Third party geolocation services in LBS: privacy requirements and research issues

The advances in positioning technologies and the emergence of geolocation standards opens up to the development of innovative location-based services (LBS), e.g., web-based LBS. These services challenge existing privacy protection solutions. For example, the position information is provided by a third party, the location provider, and this party may be not fully trusted. In this paper, we analyze the web-based LBS model. Then we outline the privacy-aware geolocation strategy which minimizes the interaction with the untrusted location provider by caching the information that is useful to determine the position in proximity of the private positions, e.g., home, which have been already visited. The deployment of this strategy requires investigating several issues and novel tools. The objective of this paper is to discuss the technical challenges and suggest directions of research towards a comprehensive privacy-preserving framework. To our knowledge, this is the first work on privacy protection against untrusted location providers

A Customizable k-Anonymity Model for Protecting Location Privacy

Continued advances in mobile networks and positioning technologies have created a strong market push for location-based services (LBSs). Examples include location-aware emergency services, location based service advertisement, and location sensitive billing. One of the big challenges in wide deployment of LBS systems is the privacy-preserving management of location-based data. Without safeguards, extensive deployment of location based services endangers location privacy of mobile users and exhibits significant vulnerabilities for abuse. In this paper, we describe a customizable k-anonymity model for protecting privacy of location data. Our model has two unique features. First, we provide a customizable framework to support k-anonymity with variable k, allowing a wide range of users to benefit from the location privacy protection with personalized privacy requirements. Second, we design and develop a novel spatio-temporal cloaking algorithm, called CliqueCloak, which provides location k-anonymity for mobile users of a LBS provider. The cloaking algorithm is run by the location protection broker on a trusted server, which anonymizes messages from the mobile nodes by cloaking the location information contained in the messages to reduce or avoid privacy threats before forwarding them to the LBS provider(s). Our model enables each message sent from a mobile node to specify the desired level of anonymity as well as the maximum temporal and spatial tolerances for maintaining the required anonymity. We study the effectiveness of the cloaking algorithm under various conditions using realistic location data synthetically generated using real road maps and traffic volume data. Our experiments show that the location k-anonymity model with multi-dimensional cloaking and tunable k parameter can achieve high guarantee of k anonymity and high resilience to location privacy threats without significant performance penalty

Localization to Enhance Security and Services in Wi-Fi Networks under Privacy Constraints

Developments of seamless mobile services are faced with two broad challenges, systems security and user privacy - access to wireless systems is highly insecure due to the lack of physical boundaries and, secondly, location based services (LBS) could be used to extract highly sensitive user information. In this paper, we describe our work on developing systems which exploit location information to enhance security and services under privacy constraints. We describe two complimentary methods which we have developed to track node location information within production University Campus Networks comprising of large numbers of users. The location data is used to enhance security and services. Specifically, we describe a method for creating geographic firewalls which allows us to restrict and enhance services to individual users within a specific containment area regardless of physical association. We also report our work on LBS development to provide visualization of spatio-temporal node distribution under privacy considerations