431 research outputs found

    Abstract State Machines 1988-1998: Commented ASM Bibliography

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    An annotated bibliography of papers which deal with or use Abstract State Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm

    Protecting Private Data in the Cloud

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    Companies that process business critical and secret data are reluctant to use utility and cloud computing for the risk that their data gets stolen by rogue system administrators at the hosting company. We describe a system organization that prevents host administrators from directly accessing or installing eaves-dropping software on the machine that holds the client's valuable data. Clients are monitored via machine code probes that are inlined into the clients' programs at runtime. The system enables the cloud provider to install and remove software probes into the machine code without stopping the client's program, and it prevents the provider from installing probes not granted by the client

    Proceedings of International Workshop "Global Computing: Programming Environments, Languages, Security and Analysis of Systems"

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    According to the IST/ FET proactive initiative on GLOBAL COMPUTING, the goal is to obtain techniques (models, frameworks, methods, algorithms) for constructing systems that are flexible, dependable, secure, robust and efficient. The dominant concerns are not those of representing and manipulating data efficiently but rather those of handling the co-ordination and interaction, security, reliability, robustness, failure modes, and control of risk of the entities in the system and the overall design, description and performance of the system itself. Completely different paradigms of computer science may have to be developed to tackle these issues effectively. The research should concentrate on systems having the following characteristics: • The systems are composed of autonomous computational entities where activity is not centrally controlled, either because global control is impossible or impractical, or because the entities are created or controlled by different owners. • The computational entities are mobile, due to the movement of the physical platforms or by movement of the entity from one platform to another. • The configuration varies over time. For instance, the system is open to the introduction of new computational entities and likewise their deletion. The behaviour of the entities may vary over time. • The systems operate with incomplete information about the environment. For instance, information becomes rapidly out of date and mobility requires information about the environment to be discovered. The ultimate goal of the research action is to provide a solid scientific foundation for the design of such systems, and to lay the groundwork for achieving effective principles for building and analysing such systems. This workshop covers the aspects related to languages and programming environments as well as analysis of systems and resources involving 9 projects (AGILE , DART, DEGAS , MIKADO, MRG, MYTHS, PEPITO, PROFUNDIS, SECURE) out of the 13 founded under the initiative. After an year from the start of the projects, the goal of the workshop is to fix the state of the art on the topics covered by the two clusters related to programming environments and analysis of systems as well as to devise strategies and new ideas to profitably continue the research effort towards the overall objective of the initiative. We acknowledge the Dipartimento di Informatica and Tlc of the University of Trento, the Comune di Rovereto, the project DEGAS for partially funding the event and the Events and Meetings Office of the University of Trento for the valuable collaboration

    Class Analysis of Object-Oriented Programs through Abstract Interpretation

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    We use abstract interpretation to define a uniform formalism for presenting and comparing class analyses for object-oriented languages. We consider three domains for class analysis derived from three techniques present in the literature, viz., rapid type analysis, a simple dataflow analysis and constraint-based 0-CFA analysis. We obtain three static analyses which are provably correct and whose abstract operations are provably optimal. Moreover, we prove that our formalisation of the 0-CFA analysis is more precise than that of the dataflow analysis

    The JCilk multithreaded language

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 103-107).JCilk is a Java-based multithreaded programming language which extends Java to provide a dynamic threading model. Specifically, JCilk imports Cilk's fork-join primitives spawn and sync into Java to provide procedure-call semantics for concurrent subcomputations. More importantly, JCilk integrates exception handling with multi-threading by defining semantics consistent with Java's existing semantics of exception handling. JCilk's strategy of integrating multithreading with Java's exception semantics yields some surprising semantic synergies. In particular, JCilk extends Java's exception semantics to allow exceptions to be passed from a spawned method to its parent in a natural way that obviates the need for Cilk's inlet and abort constructs. This extension is "faithful" in that it obeys Java's ordinary serial semantics when executed on a single processor. When executed in parallel, however, an exception thrown by a JCilk computation signals its sibling computations to abort, yielding a clean semantics in which only a single exception from the enclosing try block is handled. To minimize the complexity of reasoning about aborts, JCilk signals them "semisynchronously" so that abort signals do not interrupt ordinary serial code. Because JCilk uses Java's normal exception mechanism to propagate an abort throughout a subcomputation, the programmer can handle clean-up by simply catching a thrown CilkAbort exception. This thesis documents in detail the designed semantics, the linguistic decisions we made, and their justifications. This thesis also describes the structure of JCilk compiler and how it supports the exception semantics.(cont.) Specifically, the JCilk compiler performs a two-stage compilation process to support the continuation mechanism required by the runtime system's work-stealing algorithm. By performing static analysis, the compiler generates code to support the "catchlet" and "finallet" mechanisms for handling exceptions. The design of JCilk represents joint research with John S. Danaher and Charles E. Leiserson.by I-Ting Angelina Lee.S.M

    A Formal Model of Forth Control Words in the Pi-Calculus

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    In this paper we develop a formal specification of aspects of the Forth programming language. We describe the operation of the Forth compiler as it translates Forth control words, dealing in particular with the interpretation of immediate words during compilation. Our goal here is to provide a basis for the study of safety properties of embedded systems, many of which are constructed using Forth or Forth-like languages. To this end we construct a model of the Forth compiler in the pi-calculus, and have simulated its execution by animating this model using the Pict programming language

    Mobile Resource Guarantees for Smart Devices

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    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.

    Secure Compilation (Dagstuhl Seminar 18201)

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    Secure compilation is an emerging field that puts together advances in security, programming languages, verification, systems, and hardware architectures in order to devise secure compilation chains that eliminate many of today\u27s vulnerabilities. Secure compilation aims to protect a source language\u27s abstractions in compiled code, even against low-level attacks. For a concrete example, all modern languages provide a notion of structured control flow and an invoked procedure is expected to return to the right place. However, today\u27s compilation chains (compilers, linkers, loaders, runtime systems, hardware) cannot efficiently enforce this abstraction: linked low-level code can call and return to arbitrary instructions or smash the stack, blatantly violating the high-level abstraction. The emerging secure compilation community aims to address such problems by devising formal security criteria, efficient enforcement mechanisms, and effective proof techniques. This seminar strived to take a broad and inclusive view of secure compilation and to provide a forum for discussion on the topic. The goal was to identify interesting research directions and open challenges by bringing together people working on building secure compilation chains, on developing proof techniques and verification tools, and on designing security mechanisms

    Increasing the Performance and Predictability of the Code Execution on an Embedded Java Platform

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    This thesis explores the execution of object-oriented code on an embedded Java platform. It presents established and derives new approaches for the implementation of high-level object-oriented functionality and commonly expected system services. The goal of the developed techniques is the provision of the architectural base for an efficient and predictable code execution. The research vehicle of this thesis is the Java-programmed SHAP platform. It consists of its platform tool chain and the highly-customizable SHAP bytecode processor. SHAP offers a fully operational embedded CLDC environment, in which the proposed techniques have been implemented, verified, and evaluated. Two strands are followed to achieve the goal of this thesis. First of all, the sequential execution of bytecode is optimized through a joint effort of an optimizing offline linker and an on-chip application loader. Additionally, SHAP pioneers a reference coloring mechanism, which enables a constant-time interface method dispatch that need not be backed a large sparse dispatch table. Secondly, this thesis explores the implementation of essential system services within designated concurrent hardware modules. This effort is necessary to decouple the computational progress of the user application from the interference induced by time-sharing software implementations of these services. The concrete contributions comprise a spill-free, on-chip stack; a predictable method cache; and a concurrent garbage collection. Each approached means is described and evaluated after the relevant state of the art has been reviewed. This review is not limited to preceding small embedded approaches but also includes techniques that have proven successful on larger-scale platforms. The other way around, the chances that these platforms may benefit from the techniques developed for SHAP are discussed
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