[PAST EVENT] Dachuan Liu, Computer Science - Dissertation Defense

March 21, 2017
2:30pm - 4pm
Wren Building, Room 301
111 Jamestown Rd
Williamsburg, VA 23185Map this location

With the advancements in mobile technology, smartphones have become ubiquitous in people?s daily lives and have greatly facilitated users in many aspects. For a smartphone user, power saving and privacy protection are two important issues that matter and draw serious attentions from research communities. In this dissertation, we present our studies on some specific issues of power saving and privacy protection on a smartphone.

IEEE 802.11 Power Save Mode (PSM) cannot bring expected benefits when multiple PSM mobile devices associate to a single Access Point (AP). In this work, we first prove that the optimization of energy saving for multiple PSM clients under constraint is an NP-Complete problem. Then, we propose a solution called HPSM (Harmonious Power Saving Mechanism) to handle the contention problem. HPSM classifies a PSM client as poor or rich in terms of link resource consumption, and favors the former to save power when PSM transmission contention occurs.

Traditional user authentication methods using passcode or finger movement on smartphones are vulnerable to shoulder surfing attack, smudge attack, and keylogger attack. Eye tracking technique can reduce the risk of suffering those attacks effectively because no hand input is required. We propose a new eye tracking authentication method that utilizes the smartphone?s front camera to capture a user?s eye movement trajectories as the input of user authentication. We develop a prototype and evaluate its effectiveness on an Android smartphone.

While LBS-based apps facilitate users in many application scenarios, they raise concerns  on the breach of privacy related to location access. In this work, we perform the first measurement of this background action on the Google app market. Our investigation demonstrates that many popular apps conduct location access in background within short intervals. We further analyze the connections between characters of the action and potential privacy risk. We then propose a preliminary solution to properly handle these location requests from background.

Dachuan Liu is a Ph.D. candidate of Computer Science at William & Mary. He is advised by Dr. Haining Wang. His research interests include wireless communication, user authentication and privacy protection on smartphone. Dachuan received his Bachelor and Master in Computer Science from Sichuan University at Chengdu, Sichuan, China.