Publication Date


Document Type


Committee Members

Junjie Zhang (Advisor), Bin Wang (Committee Member), Phu H. Phung (Committee Member), Michelle Andreen Cheatham (Committee Member)

Degree Name

Doctor of Philosophy (PhD)


Security has become one of the most significant concerns for our cyberspace. Securing the cyberspace, however, becomes increasingly challenging. This can be attributed to the rapidly growing diversities and complexity of the modern cyberspace. Specifically, it is not any more dominated by connected personal computers (PCs); instead, it is greatly characterized by cyber-physical systems (CPS), embedded systems, dynamic services, and human-computer interactions. Securing modern cyberspace therefore calls for a multi-faceted approach capable of systematically integrating these emerging characteristics. This dissertation presents our novel and significant solutions towards this direction. Specifically, we have devised automated, systematic security solutions to three critical aspects of our modern cyberspace including i) cyber-physical systems, ii) dynamic web services, and iii) social networks. This dissertation makes the following contributions. First, we have conducted systematic vulnerability assessment for a real-world, complex CPS, namely Unmanned Systems Autonomy Services (UxAS). Our assessment has identified a set of exploitable vulnerabilities. Second, we have designed an adaptive traffic morphing algorithm to conceal CPS communications into background network traffic. Third, we have designed a CPS self-destruct model and studied the security-and-performance trade-off using probabilistic model checking. Fourth, we built a novel detection system to detect PHP-based malicious web shells. Finally, we have designed a novel detection system to detect suspicious behaviors in an online emotional support system.

Page Count


Department or Program

Department of Computer Science and Engineering

Year Degree Awarded


Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.