Type Checker for Annotated Assembly Programs

Abstract

The rise of speculative-execution attacks, such as Spectre, has presented a security challenge to developers. Speculation on secret data can expose it, but running without speculation is suboptimal for runtime. To fix this, researchers have been evaluating “smart” speculation schemes, which determine when to speculate and when not to in order to balance runtime with security. Our lab proposes Octal, a solution that utilizes software and hardware in tandem. Data values are marked as secret or public using type inference, and the veracity of inference is checked using a type checker. Then, hardware can separate the secret and public values. My contributions were to the type checker, as well as some scripting to evaluate results.