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Abstract. We formalise the data race free (DRF) guarantee provided by Java, as captured by the semi-formal Java Memory Model (JMM) [1] and published in the Java Language Specification [2]. The DRF guarantee says that all programs which are correctly synchronised (i.e., free of data races) can only have sequentially consistent behaviours. Such programs can be understood intuitively by programmers. Formalisation has achieved three aims. First, we made definitions and proofs precise, leading to a better understanding; our analysis found several hidden inconsistencies and missing details. Second, the formalisation lets us explore variations and investigate their impact in the proof with the aim of simplifying the model; we found that not all of the anticipated conditions in the JMM definition were actually necessary for the DRF guarantee. This allows us to suggest a quick fix to a recently discovered serious bug [3] without invalidating the DRF guarantee. Finally, the formal definition provides a basis to test concrete examples, and opens the way for future work on JMM-aware logics for concurrent programs.

Abstract. This note describes Proof General, a tool for developing machine proofs with an interactive proof assistant. Interaction is based around a proof script, which is the target of a proof development. Proof General provides a powerful user-interface with relatively little effort, alleviating the need for a proof assistant to provide its own GUI, and providing a uniform appearance for diverse proof assistants. Proof General has a growing user base and is currently used for several interactive proof systems, including Coq, LEGO, and Isabelle. Support for others is on the way. Here we give a brief overview of what Proof General does and the philosophy behind it; technical details are available elsewhere. The program and user documentation are available on the web at http://www.dcs.ed.ac.uk/home/proofgen.

Mobile health (mHealth) apps are an ideal tool for monitoring and tracking long-term health conditions; they are becoming incredibly popular despite posing risks to personal data privacy and security. In this paper, we propose a testing method for Android mHealth apps which is designed using a threat analysis, considering possible attack scenarios and vulnerabilities specific to the domain. To demonstrate the method, we have applied it to apps for managing hypertension and diabetes, discovering a number of serious vulnerabilities in the most popular applications. Here we summarise the results of that case study, and discuss the experience of using a testing method dedicated to the domain, rather than out-of-the-box Android security testing methods. We hope that details presented here will help design further, more automated, mHealth security testing tools and methods.

Abstract. We present the Mobile Resource Guarantees framework: a system for ensuring that downloaded programs are free from run-time violations of resource bounds. Certificates are attached to code in the form of efficiently checkable proofs of resource bounds; in contrast to cryptographic certificates of code origin, these are independent of trust networks. A novel programming language with resource constraints encoded in function types is used to streamline the generation of proofs of resource usage.