Calvin Deutschbein: Mining Secure Behavior of Hardware Designs (Under the direction of Cynthia Sturton)Hardware presents an enticing target for attackers attempting to gain access to a secured computer system. Software-only exploits of hardware vulnerabilities may bypass software level security features. Hardware must be made secure. However, to understand whether a hardware design is secure, security specifications must be generated to define security on that design.Micro-architectural design elements, undocumented or under-documented features, debug interfaces, and information-flow side channels all may introduce new vulnerabilities. The secure behavior of each must be specified in order ensure the design meets its security requirements and contains no vulnerabilities. However, manual efforts can be overwhelmed by design complexity, and many hardware vulnerabilities, such as Memory Sinkhole, SYSRET privilege escalation, and most recently Spectre/Meltdown, persisted in product lines for decades despite extensivetesting. An automated solution is needed to specify secure designs. Specification mining offers a solution by automating security specification for hardware. Specification miners use a form of machine learning to specify behaviors of a system by studying a system in execution. However, specification mining was first developed for use with software. Complex hardware designs offer unique challenges for this technique. Further, specification miners traditionally capture functional specifications without a notion of security, and may not use the specification logics necessary to describe some security requirements.This work demonstrates specification mining for hardware security. On CISC architectures such as x86, I demonstrate that a miner partitioning the design state space along control signals discovers a specification that includes manually defined properties and, if followed, would secure CPU designs against Memory Sinkhole and SYSRET privilege escalation. For temporal propiii