Simple Noninterference by Normalization
Carlos Tomé Cortiñas, Nachiappan Valliappan · 2019
Information-flow control (IFC) languages ensure programs preserve the confidentiality of sensitive data. Noninterference, the desired security property of such languages, states that public outputs of programs must not depend on sensitive inputs. In this paper, we show that noninterference can be proved using normalization. Unlike arbitrary terms, normal forms of programs are well-principled and obey useful syntactic properties-hence enabling a simpler proof of noninterference. Since our proof is syntax-directed, it offers an appealing alternative to traditional semantic based techniques to prove noninterference.