26,137 research outputs found
BeSpaceD: Towards a Tool Framework and Methodology for the Specification and Verification of Spatial Behavior of Distributed Software Component Systems
In this report, we present work towards a framework for modeling and checking
behavior of spatially distributed component systems. Design goals of our
framework are the ability to model spatial behavior in a component oriented,
simple and intuitive way, the possibility to automatically analyse and verify
systems and integration possibilities with other modeling and verification
tools. We present examples and the verification steps necessary to prove
properties such as range coverage or the absence of collisions between
components and technical details
Heap Abstractions for Static Analysis
Heap data is potentially unbounded and seemingly arbitrary. As a consequence,
unlike stack and static memory, heap memory cannot be abstracted directly in
terms of a fixed set of source variable names appearing in the program being
analysed. This makes it an interesting topic of study and there is an abundance
of literature employing heap abstractions. Although most studies have addressed
similar concerns, their formulations and formalisms often seem dissimilar and
some times even unrelated. Thus, the insights gained in one description of heap
abstraction may not directly carry over to some other description. This survey
is a result of our quest for a unifying theme in the existing descriptions of
heap abstractions. In particular, our interest lies in the abstractions and not
in the algorithms that construct them.
In our search of a unified theme, we view a heap abstraction as consisting of
two features: a heap model to represent the heap memory and a summarization
technique for bounding the heap representation. We classify the models as
storeless, store based, and hybrid. We describe various summarization
techniques based on k-limiting, allocation sites, patterns, variables, other
generic instrumentation predicates, and higher-order logics. This approach
allows us to compare the insights of a large number of seemingly dissimilar
heap abstractions and also paves way for creating new abstractions by
mix-and-match of models and summarization techniques.Comment: 49 pages, 20 figure
Modeling Quantum Optical Components, Pulses and Fiber Channels Using OMNeT++
Quantum Key Distribution (QKD) is an innovative technology which exploits the
laws of quantum mechanics to generate and distribute unconditionally secure
cryptographic keys. While QKD offers the promise of unconditionally secure key
distribution, real world systems are built from non-ideal components which
necessitates the need to model and understand the impact these non-idealities
have on system performance and security. OMNeT++ has been used as a basis to
develop a simulation framework to support this endeavor. This framework,
referred to as "qkdX" extends OMNeT++'s module and message abstractions to
efficiently model optical components, optical pulses, operating protocols and
processes. This paper presents the design of this framework including how
OMNeT++'s abstractions have been utilized to model quantum optical components,
optical pulses, fiber and free space channels. Furthermore, from our toolbox of
created components, we present various notional and real QKD systems, which
have been studied and analyzed.Comment: Published in: A. F\"orster, C. Minkenberg, G. R. Herrera, M. Kirsche
(Eds.), Proc. of the 2nd OMNeT++ Community Summit, IBM Research - Zurich,
Switzerland, September 3-4, 201
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New Program Abstractions for Privacy
Static program analysis, once seen primarily as a tool for optimising programs, is now increasingly important as a means to provide quality guarantees about programs. One measure of quality is the extent to which programs respect the privacy of user data. Differential privacy is a rigorous quantified definition of privacy which guarantees a bound on the loss of privacy due to the release of statistical queries. Among the benefits enjoyed by the definition of differential privacy are compositionality properties that allow differentially private analyses to be built from pieces and combined in various ways. This has led to the development of frameworks for the construction of differentially private program analyses which are private-by-construction. Past frameworks assume that the sensitive data is collected centrally, and processed by a trusted curator. However, the main examples of differential privacy applied in practice - for example in the use of differential privacy in Google Chrome’s collection of browsing statistics, or Apple’s training of predictive messaging in iOS 10 -use a purely local mechanism applied at the data source, thus avoiding the collection of sensitive data altogether. While this is a benefit of the local approach, with systems like Apple’s, users are required to completely trust that the analysis running on their system has the claimed privacy properties.
In this position paper we outline some key challenges in developing static analyses for analysing differential privacy, and propose novel abstractions for describing the behaviour of probabilistic programs not previously used in static analyses
Static Analysis of Run-Time Errors in Embedded Real-Time Parallel C Programs
We present a static analysis by Abstract Interpretation to check for run-time
errors in parallel and multi-threaded C programs. Following our work on
Astr\'ee, we focus on embedded critical programs without recursion nor dynamic
memory allocation, but extend the analysis to a static set of threads
communicating implicitly through a shared memory and explicitly using a finite
set of mutual exclusion locks, and scheduled according to a real-time
scheduling policy and fixed priorities. Our method is thread-modular. It is
based on a slightly modified non-parallel analysis that, when analyzing a
thread, applies and enriches an abstract set of thread interferences. An
iterator then re-analyzes each thread in turn until interferences stabilize. We
prove the soundness of our method with respect to the sequential consistency
semantics, but also with respect to a reasonable weakly consistent memory
semantics. We also show how to take into account mutual exclusion and thread
priorities through a partitioning over an abstraction of the scheduler state.
We present preliminary experimental results analyzing an industrial program
with our prototype, Th\'es\'ee, and demonstrate the scalability of our
approach
Supporting Cyber-Physical Systems with Wireless Sensor Networks: An Outlook of Software and Services
Sensing, communication, computation and control technologies are the essential building blocks of a cyber-physical system (CPS). Wireless sensor networks (WSNs) are a way to support CPS as they provide fine-grained spatial-temporal sensing, communication and computation at a low premium of cost and power. In this article, we explore the fundamental concepts guiding the design and implementation of WSNs. We report the latest developments in WSN software and services for meeting existing requirements and newer demands; particularly in the areas of: operating system, simulator and emulator, programming abstraction, virtualization, IP-based communication and security, time and location, and network monitoring and management. We also reflect on the ongoing
efforts in providing dependable assurances for WSN-driven CPS. Finally, we report on its applicability with a case-study on smart buildings
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