Document Type



Doctor of Philosophy (PhD)


Computer Science

First Advisor's Name

Bogdan Carbunar

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Sundaraja Sitharama Iyengar

Second Advisor's Committee Title

Committee member

Third Advisor's Name

B. M. Golam Kibria

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Niki Pissinou

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Naphtali Rishe

Fifth Advisor's Committee Title

Committee member


online social network, Data verification, Security, Video Authentication, Wearable sensors, Privacy, Fraudulent reviews, Malware, Search Rank fraud apps, Smart City, Public safety, Geosocial networks

Date of Defense



Social networks are popular platforms that simplify user interaction and encourage collaboration. They collect large amounts of media from their users, often reported from mobile devices. The value and impact of social media makes it however an attractive attack target. In this thesis, we focus on the following social media vulnerabilities. First, review centered social networks such as Yelp and Google Play have been shown to be the targets of significant search rank and malware proliferation attacks. Detecting fraudulent behaviors is thus paramount to prevent not only public opinion bias, but also to curb the distribution of malware. Second, the increasing use of mobile visual data in news networks, authentication and banking applications, raises questions of its integrity and credibility. Third, through proof-of- concept implementations, we show that data reported from wearable personal trackers is vulnerable to a wide range of security and privacy attacks, while off-the-shelves security solutions do not port gracefully to the constraints introduced by trackers. In this thesis we propose novel solutions to address these problems. First, we introduce Marco, a system that leverages the wealth of spatial, temporal and network information gleaned from Yelp, to detect venues whose ratings are impacted by fraudulent reviews. Second, we propose FairPlay, a system that correlates review activities, linguistic and behavioral signals gleaned from longitudinal app data, to identify not only search rank fraud but also malware in Google Play, the most popular Android app market. Third, we describe Movee, a motion sensor based video liveness verification system, that analyzes the consistency between the motion inferred from the simultaneously and independently captured camera and inertial sensor streams. Finally, we devise SensCrypt, an efficient and secure data storage and communication protocol for affordable and lightweight personal trackers. We provide the correctness and efficacy of our solutions through a detailed theoretic and experimental analysis.


FIDC000196 (25112 kB)
All necessary Latex files



Rights Statement

Rights Statement

In Copyright. URI:
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).