My research area is computer security. Specifically, my interests include systems security, program analysis for security, virtualization, trusted computing, and access control. I have published over 150 peer-reviewed papers on these subjects. See DBLP and Google Scholar or "See My Publications" below.

My work has been funded by the National Science Foundation ( CNS-0627551, CNS-0721579, CNS-0905343, CNS-0931914, CNS-1117692, CNS-1408880, CNS-1801534, and CNS-1816282 ), Defense Advanced Research Projects Agency, Air Force Research Lab, Army Research Lab, Office of Naval Research, Air Force Office of Scientific Research, and a number of industrial sponsors, including Google, Samsung, Cisco, and HP Labs. Their support is gratefully acknowledged.

See My Publications

Current Research Highlights

Software Security

Our NDSS 2022 paper proposes DataGuard, the first approach that fully protects safe stack objects from attacks on spatial, type, and temporal memory errors efficiently. DataGuard provides a more accurate memory safety validation analysis that extends stack protection to an average of 91.45% of all stack objects that can only be referenced safely. DataGuard reduces the overhead of using Clang’s Safe Stack defense for protection of the SPEC CPU2006 benchmarks from 11.3% to 4.3%, demonstrating that a comprehensive and accurate analysis can both increase the scope of stack data protection and reduce overheads. Also, see our other NDSS 2022 paper on incremental vulnerability detection and our2021 ACM TOPS paper on data-oriented attacks.

Mobile Security

Our USENIX Security 2021 paper proposes PolyScope, the first tool for triaging Android systems for the sources of possible filesystem access vulnerabilities comprehensively using their combination of access control policies. PolyScope is a policy analysis tool that: (1) identifies the filesystem resources that subjects are authorized to use that may be modified by their adversaries and (2) determines the specific filesystem operations that require vulnerability testing. Using PolyScope, we detect two previously unknown vulnerabilities and derive vulnerability testing requirements for nine Android and OEM versions. Also, see our 2021 IEEE S&P paper on the Android Scoped Storage defense and our 2021 IEEE Surveys paper on sensor-based threats to IoT and mobile systems.

Systems Security

Our VEE 2020 paper on Lightweight Virtual Domains (LVDs) was awarded Best Paper of the conference. LVDs provide a mechanism to isolate components (e.g., drivers) from the kernel securely within supervisor mode with good performance using the extended page table (EPT) mechanism. LVDs enforce five security invariants to prevent a variety of attacks on the kernel from the isolated components. Through novel techniques, such as exitless interrupt delivery, LVDs are able to maintain good kernel performance when using isolated components, incurring less than 5% overhead for the Phoronix benchmarks. Also, see our ACM AsiaCCS paper on Linux Security Module (LSM) performance, our HomeEndorser paper on IoT systems security, and our Pagoda paper on a low-cost code piracy defense using Intel SGX.