Structural Information Flow - A Fresh Look at Types for Non-Interference

Watch this 15-minute conference presentation from OOPSLA 2025 that introduces structural information flow, a novel approach to information flow control and non-interference properties in programming languages. Learn how researchers from Carnegie Mellon University address the practical limitations of traditional information flow type systems by drawing insights from modal logic literature to argue that information flow reasoning emerges from hybrid logic rather than conventional modal logic. Discover how structural information flow specifications are more straightforward to write and visually parse compared to existing approaches, while exploring how declassification naturally emerges as a consequence of general information flow machinery rather than an aberration to non-interference. Examine the logical relations approach used to establish non-interference and understand how this framework enables real-world information flow analysis without compromising theoretical elegance. Gain insights into security types, confidentiality, dependency tracking, and polymorphism as applied to information flow control systems that can prove secrets don't leak through computations while maintaining excellent local reasoning properties.