Yih-Chun Hu

My general research interests are in security and systems, with emphasis on the areas of secure systems and mobile communications. I have published papers in the areas of secure Internet routing, secure routing in wireless ad hoc networks, security and anonymity in peer-to-peer networks, efficient cryptographic mechanisms for routing security, and design and evaluation of ad hoc network routing protocols. In my future research, I will continue to build new systems with lightweight and minimally intrusive security. I will build systems that preserve privacy and anonymity in wireless networks to overcome attackers that can correlate individual wireless transmissions. In environments where user cooperation can be a public good, I will design techniques that incentivize user cooperation while minimizing the impact of malicious players. I will design and use evaluation frameworks that objectively, quantifiably, and rigorously measure the performance of secure systems under attack. I will also build backwards-compatible, incrementally-deployable lightweight security mechanisms for widely-deployed protocols with insufficient security.

In my current and future research, I will build systems with lightweight and minimally intrusive security. These systems will allow users to perform useful computation, efficiently use scarce resources such as bandwidth and radio spectrum, and preserve their anonymity when necessary. In the next few years, I will focus my efforts on security in Internet and mobile computing systems.

Internet Security

Many core Internet protocols, such as routing, reliable transport, name resolution, and email, were developed without security mechanisms, coordinated and instantaneous deployment of a revised, secure protocol is unrealistic due to the current widespread deployment of the existing protocols. In my future work, I will study security for such protocols, with a special emphasis on incremental deployment properties. End system security is another important area of Internet research. Millions of end systems have been compromised and are being used to distribute spam and launch Distributed Denial-of-Service (DDoS) attacks. Compromised end systems also can damage the integrity of many important commercial applications, such as online banking and electronic commerce. The two major causes of system compromise are software vulnerabilities and user error. I am interested in techniques that can detect attacks that compromise end systems, and also in user interfaces that allow a user to understand their exposure to risk. Many Internet applications are based on a client-server architecture, which leaves them vulnerable to single points of failure. Recently, researchers have proposed techniques to shift such applications to a peer-to-peer architecture, allowing a higher level of robustness. I am interested in leveraging my experience with securing ad hoc network routing, using it to continue my work in secure peer-to-peer overlays and applications.

Mobile Computing Security

Mobile computing is improving at an incredible pace, and networking is an increasingly important part of mobile computing. Many access technologies are connecting mobile devices to the Internet, such as cellular data protocols (e.g., UMTS and CDMA2000 1xEV-DO), data-only networks (e.g., those used by the RIM Blackberry), and WiFi networks. The success ofWiFi is leading to the development of additional unlicensed networks such as WiMAX (IEEE 802.16). Mobile communications devices will soon incorporate several different wireless technologies in a single device, with each wireless technology providing different levels of coverage, bandwidth, and cost. The variety and extensive coverage of these networks raise interesting research challenges in exploiting synergies between the networks and adapting applications to highly variable levels of service. An emerging research area in this space is that of hybrid networks. For example, packets normally sent directly over a cellular network can instead be passed hop-by-hop over a wireless ad hoc network to a proxy closer to the cellular base station. In such networks, base stations communicate primarily with mobile stations that have high signal-to-noise ratios, resulting in better spectrum efficiency. As mobile communications technologies become more widespread, they become more attractive to attack. Especially vulnerable are protocols such as WiFi, for which several hardware implementations are available and which operate in unlicensed spectrum. Applications such as hybrid networks need security before they can be deployed by cellular network operators. I am currently working on incentives for cooperation in hybrid networks, as well as secure protocols that limit the impact of malicious participants. Other areas in mobile computing security that I intend to pursue include privacy concerns in cellular and ad hoc networks, secure routing in ad hoc networks, secure proofs of location, and secure medium access control protocols.

Copyright © 2002-2009 Yih-Chun Hu. The views and opinions expressed on this page are those of Yih-Chun Hu, and may not reflect the opinions or views of the State of Illinois, the University of Illinois, ECE, CSL, ITI, CRHC, or any funding agency that supports my work. The photograph of downtown Chicago is © 2007 Yih-Chun Hu; Canon 350D, EF-S 17-55mm f/2.8 IS @ 17mm, 25s @ f/13, ISO 100.