Most analysis methods for information flow properties do not consider temporal restrictions. In practice, however, such properties rarely occur statically, but have to consider constraints such as when and under which conditions a variable has to be kept secret. In this paper, we propose a natural integration of information flow properties into linear-time temporal logics (LTL). We add a new modal operator, the hide operator, expressing that the observable behavior of a system is independent of the valuations of a secret variable. We provide a complexity analysis for the model checking problem of the resulting logic SecLTL and we identify an expressive fragment for which this question is efficiently decidable. We also show that the path based nature of the hide operator allows for seamless integration into branching time logics.

Information flow properties of programs can be formalized as hyperproperties specifying the relation of multiple executions. In this paper, we therefore introduce a framework for proving 2-hypersafety properties by means of abstract interpretation. The main idea is to apply abstract interpretation on the self-compositions of the control flow graphs of programs. As a result, our method is inherently capable of analyzing relational properties of even dissimilar programs.Constructing self-compositions of control flow graphs is nontrivial. Therefore, we present an algorithm for constructing quality self-compositions driven by a tree distance measure between the abstract syntax trees of subprograms. Finally, we demonstrate the applicability of the approach by proving intricate information flow properties of programs written in a simple language for tree manipulation motivated by the Web Services Business Process Execution Language.

A transition metal free route to phosphetes featuring an exocyclic alkene unit is presented. In this approach phosphanides are added to a variety of diynes generating phosphaallylic intermediates which depending on the reaction conditions transform either to phosphetes or the corresponding phospholes. Investigation of the reaction mechanism by combined quantum chemical and experimental means identifies phosphole formation as thermodynamically controlled reaction path, whereas kinetic control furnishes the corresponding phosphetes. Structural and luminescence properties of the rare class of phosphetes are explored, as well as for selected key intermediates.

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We introduce a novel way of proving information flow properties of a program based on its self-composition. Similarly to the universal information flow type system of Hunt and Sands, our analysis explicitly computes the dependencies of variables in the final state on variables in the initial state. Accordingly, the analysis result is independent of specific information flow lattices, and allows to derive information flow w.r.t. any of these. While our analysis runs in polynomial time, we prove that it never loses precision against the type system of Hunt and Sands, and may gain extra precision by taking similarities between different branches of conditionals into account. Also, we indicate how it can be smoothly generalized to an interprocedural analysis.