10 research outputs found

    Collaborative verification of information flow for a high-assurance app store.

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    ABSTRACT Current app stores distribute some malware to unsuspecting users, even though the app approval process may be costly and timeconsuming. High-integrity app stores must provide stronger guarantees that their apps are not malicious. We propose a verification model for use in such app stores to guarantee that the apps are free of malicious information flows. In our model, the software vendor and the app store auditor collaborate -each does tasks that are easy for her/him, reducing overall verification cost. The software vendor provides a behavioral specification of information flow (at a finer granularity than used by current app stores) and source code annotated with information-flow type qualifiers. A flow-sensitive, context-sensitive information-flow type system checks the information flow type qualifiers in the source code and proves that only information flows in the specification can occur at run time. The app store auditor uses the vendor-provided source code to manually verify declassifications. We have implemented the information-flow type system for Android apps written in Java, and we evaluated both its effectiveness at detecting information-flow violations and its usability in practice. In an adversarial Red Team evaluation, we analyzed 72 apps (576,000 LOC) for malware. The 57 Trojans among these had been written specifically to defeat a malware analysis such as ours. Nonetheless, our information-flow type system was effective: it detected 96% of malware whose malicious behavior was related to information flow and 82% of all malware. In addition to the adversarial evaluation, we evaluated the practicality of using the collaborative model. The programmer annotation burden is low: 6 annotations per 100 LOC. Every sound analysis requires a human to review potential false alarms, and in our experiments, this took 30 minutes per 1,000 LOC for an auditor unfamiliar with the app

    Score-P: Scalable performance measurement infrastructure for parallel codes (v8.0)

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    The Score-P measurement infrastructure is a highly scalable and easy-to-use tool suite for profiling, event tracing, and online analysis of HPC applications. Score-P offers the user a maximum of convenience by supporting a number of analysis tools. Currently, it works with CubeGUI, Scalasca trace tools, Vampir, Tau, and Extra-P and is open for other tools. Score-P comes together with the new Open Trace Format Version 2, the Cube4 profiling format and the Opari2 instrumenter. Score-P is available under the 3-clause BSD Open Source license

    Score-P: Scalable performance measurement infrastructure for parallel codes (v8.3)

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    The instrumentation and measurement framework Score-P, together with analysis tools build on top of its output formats, provides insight into massively parallel HPC applications, their communication, synchronization, I/O, and scaling behaviour to pinpoint performance bottlenecks and their causes. Score-P is a highly scalable and easy-to-use tool suite for profiling (summarizing program execution) and event tracing (capturing events in chronological order) of HPC applications. The scorep instrumentation command adds instrumentation hooks into a user's application by either prepending or replacing the compile and link commands. C, C++, Fortran, and Python codes as well as contemporary HPC programming models (MPI, threading, GPUs, I/O) are supported. When running an instrumented application, measurement event data is provided by the instrumentation hooks to the measurement core. There, the events are augmented with high-accuracy timestamps and potentially hardware counters (a plugin-API allows querying additional metric sources). The augmented events are then passed to one or both of the built-in event consumers, profiling and tracing (a plugin-API allows creation of additional event consumers) which finally provide output in the formats CUBE4 and OTF2, respectively. Score-P is available under the 3-clause BSD Open Source license
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