Abstract We present a relational program logic for reasoning about information flow properties formalised in an assertion language based on partial equivalence relations. We define and prove the soundness of the logic, a proof technique for precise, logic-based information flow properties. The logic extends Hoare logic and its unary state predicates to binary PER-based predicates for relating observationally equivalent states. A salient feature of the logic is that it is capable of reasoning about programs that test on secret data in a secure manner.

The idea of pushing computation to storage devices has been explored for decades, without widespread adoption so far. The definition of Computational Programs namespaces in NVMe (TP 4091) might be a breakthrough. The proposal defines device-specific programs, that are installed statically, and downloadable programs, offloaded from a host at run-time using eBPF. In this paper, we present the design and implementation of Delilah, the first public description of an actual computational storage device supporting eBPF-based code offload. We conduct experiments to evaluate the overhead of eBPF function execution in Delilah, and to explore design options. This study constitutes a baseline for future work.

The skyline operator has recently emerged as an alternative to ranking queries. It retrieves a number of potential best options for arbitrary monotone preference functions. The success of this operator in the database community is based on the belief that users benefit from the limited effort required to specify skyline queries compared to, for instance, ranking. While application examples of the skyline operator exist, there is no principled analysis of its benefits and limitations in data retrieval tasks. Our study investigates the degree to which users understand skyline queries, how they specify query parameters and how they interact with skyline results made available in listings or map-based interfaces.

We aim to specify program transformations in a declarative style, and then to generate executable program transformers from such specifications. Many transformations require non-trivial program analysis to check their applicability, and it is prohibitively expensive to re-run such analyses after each transformation. It is desirable, therefore, that the analysis information is incrementally updated.We achieve this by drawing on two pieces of previous work: first, Bernhard Steffen's proposal to use model checking for certain analysis problems, and second, John Conway's theory of language factors. The first allows the neat specification of transformations, while the second opens the way for an incremental implementation. The two ideas are linked by using regular patterns instead of Steffen's modal logic: these patterns can be viewed as queries on the set of program paths.