The boom of electronic commerce requires existence and use of reliable means of authentication of communicating parties. We need an analogy of hand-written signature that can be applied to electronic documents. We sha...
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The boom of electronic commerce requires existence and use of reliable means of authentication of communicating parties. We need an analogy of hand-written signature that can be applied to electronic documents. We shall call such a concept an electronic signature. There is a current trend to make electronic signatures meeting some requirements equal to hand-written signatures. This makes it a very powerful tool but, on the other hand, there are some sensitive security issues that have to be discussed and that the potential users should be aware of. In this article we would like to point out some of these issues and especially those that all electronic signature users are affected by. We have to say, it is very unwise to use a software only implementation on a non-dedicated hardware to create electronic signatures if the responsibility for such signature is not limited. Using a hardware cryptographic module that is incapable of displaying the data to be signed may still be unsatisfactory. Using a module without an independent input for authorization data does not help much, a module with an independent input is significantly better but the danger is still far from negligible. Using a dedicated system to create electronic signatures can solve many of the problems. On the other hand, it is the most expensive solution considered. We will describe a solution that is both relatively cheap and reasonably secure. We also suggest some affordable key management solutions.
Enterprise data backup is always a mission critical as well as resource straining operation. In the light of recent surge in near peta-byte databases universities are particularly searching for scalable solutions. Mos...
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Software systems are not just math.matical structures. The majority are also cognitive artefacts that rely on the ability of their users to understand and interpret information provided via an interface, and to act on...
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Software systems are not just math.matical structures. The majority are also cognitive artefacts that rely on the ability of their users to understand and interpret information provided via an interface, and to act on that information using actions provided by the system. The design of an interactive system must thus account for both the technical requirements of the given domain, and the cognitive abilities of the user. However, the disciplines involved (computerscience and psychology) traditionally operate with quite different methods and techniques, making it difficult to integrate their respective insights into system design. This paper reports on work that is creating a framework for interaction that encompasses both the description of complex software systems and the cognitive resources needed to operate those systems. An interface for supporting gestural interaction is used to illustrate the approach. The paper concludes with an assessment of the prospects for this kind of integrative modeling and sets out key areas for future progress.
We prove that with high probability a skip graph contains a 4-regular expander as a subgraph, and estimate the quality of the expansion via simulations. As a consequence skip graphs contain a large connected component...
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ISBN:
(纸本)9781581139860
We prove that with high probability a skip graph contains a 4-regular expander as a subgraph, and estimate the quality of the expansion via simulations. As a consequence skip graphs contain a large connected component even after an adversarial deletion of nodes. We show how the expansion property could be used to sample a node in the skip graph in a highly efficient manner. We also show that the expansion property could be used to load balance the skip graph quickly. Finally it is shown that the skip graph could serve as an unstructured P2P system, thus it is a good candidate for a hybrid P2P system. Copyright 2005 ACM.
The paper describes the application porting process onto the EGEE grid of GROMACS package that was carried out using the P-GRADE Grid Portal tool implemented in COMPCHEM. For this purpose a new stategy to access local...
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We study the problem of computing the visibility graph defined by a set P of n points inside a polygon Q: two points p, q Ε P are joined by an edge if the segment pq ⊂ Q. Efficient output-sensitive algorithms are kno...
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We study the problem of computing the visibility graph defined by a set P of n points inside a polygon Q: two points p, q Ε P are joined by an edge if the segment pq ⊂ Q. Efficient output-sensitive algorithms are known for the case in which P is the set of all vertices of Q. We examine the general case in which P is an arbitrary set of points, interior or on the boundary of Q and study a variety of algorithmic questions. We give an output-sensitive algorithm, which is nearly optimal, when Q is a simple polygon. We introduce a notion of "fat" or "robust" visibility, and give a nearly optimal algorithm for computing visibility graphs according to it, in polygons Q that may have holes. Other results include an algorithm to detect if there are any visible pairs among P, and algorithms for output-sensitive computation of visibility graphs with distance restrictions, invisibility graphs, and rectangle visibility graphs.
This paper presents an evolution strategy used to infer fuzzy finite-state automata from examples of a fuzzy language. We describe the fitness function of an generated automata with respect to a set of examples of a f...
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ISBN:
(纸本)0780390172
This paper presents an evolution strategy used to infer fuzzy finite-state automata from examples of a fuzzy language. We describe the fitness function of an generated automata with respect to a set of examples of a fuzzy language, the representation of the transition of the automata as well as the output of the states in the evolution strategy and the simple mutation operators that work on these representations. Results are reported on the inference of a fuzzy language.
Many Android apps have a legitimate need to communicate over the Internet and are then responsible for protecting potentially sensitive data during transit. This paper seeks to better understand the potential security...
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Due to the increasing number of conferences, researchers need to spend more and more time browsing through the respective calls for papers (CFPs) to identify those conferences which might be of interest to them. In th...
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We present a new scheduling algorithm Odd-Even4, which not only guarantees the hard deadlines of all periodic tasks with fewer context switches but also minimizes the average response time of bounded predictable tasks...
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