Witnessing Secure Compilation

Kedar S. Namjoshi, Lucas M. Tabajara

Abstract: Compiler optimizations may break or weaken the security properties of a source program. This work develops a translation validation methodology for secure compilation. A security property is expressed as an automaton operating over a bundle of program traces. A refinement proof scheme derived from a property automaton guarantees that the associated security property is preserved by a program transformation. This generalizes known refinement methods that apply only to specific security properties. In practice, the refinement relations (“security witnesses”) are generated during compilation and validated independently with a refinement checker. This process is illustrated for common optimizations. Crucially, it is not necessary to formally verify the compiler implementation, which is infeasible for production compilers.