This paper revisits a problem that was identified by Kramer and Magee: placing a system in a consistent state before and after runtime changes (1990). We show that their notion of quiescence as a necessary and suffici...
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This paper revisits a problem that was identified by Kramer and Magee: placing a system in a consistent state before and after runtime changes (1990). We show that their notion of quiescence as a necessary and sufficient condition for safe runtime changes is too strict and violates the black-box design principle. We introduce a weaker condition, tranquility; easier to obtain, less disruptive for the system and still sufficient to ensure application consistency. We also present an implementation of this concept in a component middleware platform
Cyber theft is a serious threat to Internet security. It is one of the major security concerns by both network service providers and Internet users. Though sensitive information can be encrypted when stored in non-vol...
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Cyber theft is a serious threat to Internet security. It is one of the major security concerns by both network service providers and Internet users. Though sensitive information can be encrypted when stored in non-volatile memory such as hard disks, for many e-commerce and network applications, sensitive information is often stored as plaintext in main memory. Documented and reported exploits facilitate an adversary stealing sensitive information from an application's memory. These exploits include illegitimate memory scan, information theft oriented buffer overflow, invalid pointer manipulation, integer overflow, password stealing Trojans and so forth. Today's computing system and its hardware cannot address these exploits effectively in a coherent way. This paper presents a unified and lightweight solution, called InfoShield that can strengthen application protection against theft of sensitive information such as passwords, encryption keys, and other private data with a minimal performance impact. Unlike prior whole memory encryption and information flow based efforts, InfoShield protects the usage of information. InfoShield ensures that sensitive data are used only as defined by application semantics, preventing misuse of information. Comparing with prior art, InfoShield handles a broader range of information theft scenarios in a unified framework with less overhead. Evaluation using popular network client-server applications shows that InfoShield is sound for practical use and incurs little performance loss because InfoShield only protects absolute, critical sensitive information. Based on the profiling results, only 0.3% of memory accesses and 0.2% of executed codes are affected by InfoShield.
In the near future, all Chinese banks will transmit sensitive financial data over the Chinese National Financial Network (CNFN). The key to making the CNFN trusted is to provide it with essential security mechanisms. ...
In the near future, all Chinese banks will transmit sensitive financial data over the Chinese National Financial Network (CNFN). The key to making the CNFN trusted is to provide it with essential security mechanisms. These include the authen-tication of the user, assuring transaction confidentiality, data integrity and nonrepudiation. Various technologies can be used to secure the CNFN, such as data encryption, and the use of the one-way hash function and the digital signature.
In robust regression we often have to decide how many are the unusualobservations, which should be removed from the sample in order to obtain better fitting for the restof the observations. Generally, we use the basic...
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In robust regression we often have to decide how many are the unusualobservations, which should be removed from the sample in order to obtain better fitting for the restof the observations. Generally, we use the basic principle of LTS, which is to fit the majority ofthe data, identifying as outliers those points that cause the biggest damage to the robust ***, in the LTS regression method the choice of default values for high break down-point affectsseriously the efficiency of the estimator. In the proposed approach we introduce penalty cost fordiscarding an outlier, consequently, the best fit for the majority of the data is obtained bydiscarding only catastrophic observations. This penalty cost is based on robust design weights andhigh break down-point residual scale taken from the LTS estimator. The robust estimation is obtainedby solving a convex quadratic mixed integer programming problem, where in the objective functionthe sum of the squared residuals and penalties for discarding observations is minimized. Theproposed mathematical programming formula is suitable for small-sample data. Moreover, we conduct asimulation study to compare other robust estimators with our approach in terms of their efficiencyand robustness.
A new field in distributed computing, called Ambient Intelligence, has emerged as a consequence of the increasing availability of wireless devices and the mobile networks they induce. Developing software for such mobi...
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A new field in distributed computing, called Ambient In-telligence, has emerged as a consequence of the increasing availability of wireless devices and the mobile networks they induce. Developing software for such mob...
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The paper studies the systematic top-down design of a ternary asynchronous multiplexer refining its communication-oriented input/output behaviour into a state-based implementation. The formal design exploits two impor...
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ISBN:
(纸本)9781604234558
The paper studies the systematic top-down design of a ternary asynchronous multiplexer refining its communication-oriented input/output behaviour into a state-based implementation. The formal design exploits two important transformations: differentiation localizes the effect of single inputs wrt. an input history, abstraction extracts the component's control state and data state from the previous input history.
The benefits associated with separation of concerns are well established. Aspect-Orientation is a methodology that aims at separating components and aspects from the early stages of the software life cycle, and using ...
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ISBN:
(纸本)9781932415490
The benefits associated with separation of concerns are well established. Aspect-Orientation is a methodology that aims at separating components and aspects from the early stages of the software life cycle, and using techniques to combining them together at the implementation phase. Componentbased programming systems have shown themselves to be a natural way of constructing extensible software. Well-defined interfaces, encapsulation, late binding and polymorphism promote extensibility, yet despite this synergy, components have not been widely employed at the systems level. This is primarily due to the failure of existing component technologies to provide the protection and performance required of systems software. In this paper we identify the requirements for a component system to support extensions, and describe an extensibility and adaptability in the design of system software. We discuss an aspect-oriented framework that can simplify system design by expressing it at a higher level of abstraction. Our work concentrates on how to achieve a higher separation of aspects, components, and layers from each other. Our goal is to achieve a better design model for system software in terms of extensibility, reuse and adaptability.
The distributed evaluation of functional programs and the communication between computational nodes require high-level process description and coordination mechanism. This paper presents the D-Clean high-level functio...
The distributed evaluation of functional programs and the communication between computational nodes require high-level process description and coordination mechanism. This paper presents the D-Clean high-level functional language, which supports the distributed computation of Clean functions over a cluster. The lazy functional programming language Clean is extended by new language elements in order to achieve parallel features. The distributed computations of functions are expressed in the form of process-networks. D-Clean introduces language primitives to control the dataflow in a distributed process-network. A process scheme defines a partial computation graph, where the nodes are functions to be evaluated and the edges are communication channels. The computational nodes are implemented as statically typed Clean programs. The schemes are parameterized by functions, types and data for defining process networks. D-Clean is compiled to an intermediate level language called D-Box. The D-Clean generic constructs are instantiated into D-Box expressions. D-Box is designed for the description of the computational nodes. D-Box expressions hide implementation details and enable direct control over the process-network. The asynchronous communication is based on language-independent middleware services. The present paper provides the syntax and the informal semantics of both coordination languages. To illustrate the definition of a distributed functional computational pattern using the D-Clean language a farm skeleton running example is presented.
In this paper we present the LearnLib, a library for automata learning and experimentation. Its modular structure allows users to configure their tailored learning scenarios, which exploit specific properties of the e...
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ISBN:
(纸本)1595931481
In this paper we present the LearnLib, a library for automata learning and experimentation. Its modular structure allows users to configure their tailored learning scenarios, which exploit specific properties of the envisioned applications. As has been shown earlier, exploiting application-specific structural features enables optimizations that may lead to performance gains of several orders of magnitude, a necessary precondition to make automata learning applicable to realistic scenarios. Copyright 2005 ACM.
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