Document Type

Open Access Thesis

Embargo Period

12-26-2016

Degree Program

Electrical & Computer Engineering

Degree Type

Master of Science in Electrical and Computer Engineering (M.S.E.C.E.)

Year Degree Awarded

2017

Month Degree Awarded

February

Advisor Name

Hossein

Advisor Last Name

Pishro-Nik

Co-advisor Name

Amir

Co-advisor Last Name

Houmansadr

Third Advisor Name

Dennis

Third Advisor Last Name

Goeckel

Abstract

The popularity of mobile devices and location-based services (LBS) have created great concerns regarding the location privacy of the users of such devices and services. Anonymization is a common technique that is often being used to protect the location privacy of LBS users. This technique assigns a random pseudonym to each user and these pseudonyms can change over time. Here, we provide a general information theoretic definition for perfect location privacy and prove that perfect location privacy is achievable for mobile devices when using the anonymization technique appropriately. First, we assume that the user’s current location is independent from her past locations. Using this i.i.d model, we show that if the pseudonym of the user is changed before O(n2/(r−1)) number of anonymized observations is made by the adversary for that user, then she has perfect location privacy, where n is the number of users in the network and r is the number of all possible locations that the user might occupy. Then, we model each user’s movement by a Markov chain so that a user’s current location depends on his previous locations, which is a more realistic model when approximating real world data. We show that perfect location privacy is achievable in this model if the pseudonym of the user is changed before O(n2/(|E|−r)) anonymized observations is collected by the adversary for that user where |E| is the number of edges in the user’s Markov model.

First Advisor

Hossein Pishro-Nik

Second Advisor

Amir Houmansadr

Third Advisor

Dennis Goeckel

Share

COinS