I have been working on privacy-enhancing federated information sharing and proposed a secure multi-organizational information sharing framework to support distributed privacy-preserving data access in business intelligence systems and health information exchange systems.

Current Projects

Anonymous Routing

Anonymous rotuing enables people to hide their identity in communication over the Internet. Most of the existing anonymous routing protocols rely on a relative small set of pre-selected relay servers to redirect the messages. The pre-selection approaches provide good anonymity, but suffer from node failures and scalability problem. In this project, we develope a node-failure-resilient anonymous, CAT (Communtative Anonymous Tunnel), to allow the initiator to explore an anonymous tunnel consisting of several valid anonymous paths via a probing process, and hop among them when the active path encounters a node failure.

Related publications:

  1. Fengjun Li, Bo Luo, Peng Liu, and Chao-Hsien Chu. A Node-failure-resilient Anonymous Communication Protocol through Commutative Path Hopping, Proceedings of the 29th IEEE Conference on Computer Communications (INFOCOM), March 2010. San Diego, CA. [pdf] (acceptance rate: 17%)
Smart Grid Security

In the Smart Grid Secure Data Communication project, we have proposed one of the first solutions to address both security and privacy concerns relating to collecting real-time fine-grained smart metering data in neighborhood area networks. We have developed a set of algorithms for privacy-preserving data encryption and the corresponding integrity verification and false data detection.

Related publications:

  1. Lei Yang and Fengjun Li. Detecting False Data Injection in Smart Grid In-Network Aggregation, the 4th IEEE International Conference on Smart Grid Communications (SmartGridComm), October 2013. Vancouver, Canada.
  2. Fengjun Li and Bo Luo. Preserving Data Integrity for Smart Grid Data Aggregation, IEEE SmartGridComm, Novermber, 2012. Taina, Taiwan.
  3. Fengjun Li, Bo Luo, and Peng Liu. Secure and Privacy-Preserving Information Aggregation for Smart Grids, International Journal of Security and Networks, Special Issue on Security and Privacy in Smart Grid, 6(1):28 - 39, 2011.
  4. Fengjun Li, Bo Luo, and Peng Liu. Secure Information Aggregation for Smart Grids Using Homomorphic Encryption, Proceedings of the 1st IEEE Conference on Smart Grid Communications (SmartGridComm), October 2010. Gaithersburg, MD. [pdf]
Online Review Spam Detection

Customers' reviews would greatly affect others’ purchase decision making. It becomes an increasing incentive for review spammers to manipulate the reviews. Thus, the detection of review spams and a trustworthy measure of the credability of the review are critical to online review sites and the online retailers. In this research thrust, we aim to create a robust spam measurement and detection model that incorporates both content and structure features.

Related publications:

  1. Yingying Ma and Fengjun Li. Detecting Review Spam: Challenges and Opportunities, Collaborative Communities for Social Computing (CCSocialComp) Workshop, October 2012. Pittsburgh, PA. (invited paper)

Past Projects

Protecting Data Privacy in Online Social Networks

Privacy is becomg an increasing concern in applications related to online social networks. In these "uncontrolled" environments, individuals create, share and propagate information voluntarily. The objective of the privacy studies in OSN is to find answers to essential questions as “how identifiable an individual is from scattered information pieces over social media” and “how to protect the privacy of personal information from being unknowingly revealed”.

Related publications:

  1. Yuhao Yang, Jonathan Lutes, Fengjun Li, Bo Luo and Peng Liu. Stalking Online: on User Privacy in Social Networks, ACM Conference on Data and Application Security and Privacy (CODASPY), 2012. (acceptance rate: 18.6%)
  2. Fengjun Li, Xukai Zhou, Peng Liu, and JakeY. Chen. New Threats to Health Data Privacy, BMC Bioinformatics 2011, 12(Suppl 12):S7.
  3. Fengjun Li, Jake Y. Chen, Xukai Zou, and Peng Liu. New Privacy Threats in Healthcare Informatics: When Medical Records Join the Web, Proceedings of the 9th International Workshop on Data Mining in Bioinformatics (BIOKDD), July 2010. Washington, DC. [pdf] (short paper)
  4. Fengjun Li, Bo Luo, Peng Liu, and Chao-Hsien Chu. A Node-failure-resilient Anonymous Communication Protocol through Commutative Path Hopping, Proceedings of the 29th IEEE Conference on Computer Communications (INFOCOM), March 2010. San Diego, CA. [pdf] (acceptance rate: 17%)
Secure and Privacy-Preserving Distributed Information Sharing

This research aims to support privacy-enhancing federated information sharing across multiple organizations with various information sharing needs and requirements upon different levels of trust. We have proposed a secure multi-organizational information sharing framework to support distributed privacy-preserving data access in business intelligence systems and health information exchange systems. This Privacy-Preserving Information Brokering (PPIB) framework combines XML access control enforcement mechanism with content-based inquiry routing across databases belonging to multiple alliance organizations, and seamlessly integrates both functionalities into a set of nondeterministic finite automata (known as information brokers).

Related publications:

  1. Fengjun Li, Bo Luo, Peng Liu, Dongwon Lee, and Chao-Hsien Chu. Enforcing Secure and Privacy-Preserving Information Brokering in Distributed Information Sharing. In IEEE Transactions on Information Forensics and Security, 8(6):888-900, June 2013.
  2. Fengjun Li, Yuxin Chen, Bo Luo, Dongwon Lee, and Peng Liu. Privacy Preserving Group Linkage, the 23rd Scientific and Statistical Database Management Conference (SSDBM), July 2011. Portland, OR.
  3. Fengjun Li, Bo Luo, Peng Liu, Dongwon Lee, Prasenjit Mitra, Wang-Chien Lee, Chao-Hsien Chu. In-broker Access Control for Information Brokerage Systems, International Journal on Intelligent Control and Systems, Special Issue on Information Assurance, 12(4):283-292, 2007. [pdf]
  4. Fengjun Li, Bo Luo, Peng Liu, Anna Squicciarini, Dongwon Lee, and Chao-Hsien Chu. Defending against Attribute-Correlation Attacks in Privacy-Aware Information Brokering, Proceedings of the 4th International Conference on Collaborative Computing: Networking, Applications and Worksharing (CollaborateCom), November, 2008. Orlando, FL. [pdf] (invited paper)
  5. Fengjun Li, Bo Luo, Peng Liu, Dongwon Lee, Chao-Hsien Chu. Automaton Segmentation: A New Approach to Preserve Privacy in XML Information Brokering. Proceedings of the 14th ACM Conference on Computer and Communication Security (CCS), October 2007. Alexandria, VA. (Acceptance rate: 18%) [pdf]
  6. Fengjun Li, Bo Luo, Peng Liu, Dongwon Lee, Prasenjit Mitra, Wang-Chien Lee, Chao-Hsien Chu. In-broker Access Control: Towards Efficient End-to-End Performance of Information Brokerage Systems, Proceedings of the IEEE International Conference on Sensor Networks, Ubiquitous, and Trustworthy Computing (SUTC), June 2006. Taichung, Taiwan. [pdf] (acceptance rate: 25%)