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arXiv · 2010.13191

Giving Semantics to Program-Counter Labels via Secure Effects

Andrew K. Hirsch·Ethan Cecchetti
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Abstract

Type systems designed for information-flow control commonly use a program-counter label to track the sensitivity of the context and rule out data leakage arising from effectful computation in a sensitive context. Currently, type-system designers reason about this label informally except in security proofs, where they use ad-hoc techniques. We develop a framework based on monadic semantics for effects to give semantics to program-counter labels. This framework leads to three results about program-counter labels. First, we develop a new proof technique for noninterference, the core security theorem for information-flow control in effectful languages. Second, we unify notions of security for different types of effects, including state, exceptions, and nontermination. Finally, we formalize the folklore that program-counter labels are a lower bound on effects. We show that, while not universally true, this folklore has a good semantic foundation.

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Andrew K. Hirsch, Ethan Cecchetti. 2020-10-25. Giving Semantics to Program-Counter Labels via Secure Effects. https://doi.org/10.1145/3434316

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