Social processes and proofs of theorems and programs, revisited

ABSTRACT

Language-based security is a protection mechanism that allows software components to interact in a shared address space, such that each component is guaranteed to respect its interfaces and not steal or corrupt internal data of other components. This protection mechanism is complicated to implement correctly, so we might want a formal verification of it.But we know by a famous result of DeMillo, Lipton, and Perlis (POPL 1978) that formal verification (1) is not what mathematicians do, (2) can never be practical, and (3) cannot tell us anything truly useful. Is this still true 25 years later?The question is, then, how can we carefully skirt the legitimate objections of DeMillo et al. and successfully use formal verification in a context where it can do some good. I'll talk about Foundational Proof-Carrying Code, a machine-checked soundness proof for a protection mechanism usable in Java-like virtual machines.