Journey Beyond Full Abstraction: Exploring Robust Property Preservation for Secure Compilation

TL;DR

This paper explores a broad spectrum of formal secure compilation criteria based on robust property preservation, introducing new criteria, characterizations, and proving the feasibility of achieving the strongest criteria with a simple translation.

Contribution

It introduces a comprehensive framework for secure compilation based on robust property preservation, including new criteria, characterizations, and proof techniques, expanding beyond full abstraction.

Findings

Many new secure compilation criteria proposed.

Some criteria are easier to achieve and prove than full abstraction.

Achieves the strongest criterion for a simple language translation.

Abstract

(CROPPED TO FIT IN ARXIV'S SILLY LIMIT. SEE PDF FOR COMPLETE ABSTRACT.) We are the first to thoroughly explore a large space of formal secure compilation criteria based on robust property preservation, i.e., the preservation of properties satisfied against arbitrary adversarial contexts. We study robustly preserving various classes of trace properties such as safety, of hyperproperties such as noninterference, and of relational hyperproperties such as trace equivalence. This leads to many new secure compilation criteria, some of which are easier to practically achieve and prove than full abstraction, and some of which provide strictly stronger security guarantees. For each of the studied criteria we propose an equivalent "property-free" characterization that clarifies which proof techniques apply. For relational properties and hyperproperties, which relate the behaviors of multiple programs, our formal definitions of the property classes themselves are novel. We order our criteria by their relative strength and show several collapses and separation results. Finally, we adapt existing proof techniques to show that even the strongest of our secure compilation criteria, the robust preservation of all relational hyperproperties, is achievable for a simple translation from a statically typed to a dynamically typed language.