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The <i>Border Gateway Protocol (BGP)</i> controls inter-domain routing in the Internet. BGP is vulnerable to many attacks, since routers rely on hearsay information from neighbors. <i>Secure BGP (S-BGP)</i> uses DSA to provide route authentication and mitigate many of these risks. However, many performance and deployment issues prevent S-BGP's real-world(More)
Physical systems are inherently parallel; intuition suggests that simulations of these systems may be amenable to parallel execution. The parallel execution of a discrete-event simulation requires careful synchronization of processes in order to ensure the execution's correctness; this synchronization can degrade performance. Largely negative results were(More)
The development of techniques for quantitative, model-based evaluation of computer system dependability has a long and rich history. A wide array of model-based evaluation techniques is now available, ranging from combinatorial methods, which are useful for quick, rough-cut analyses, to state-based methods, such as Markov reward models, and detailed,(More)
In this paper we introduce a new class of stochastic Petri nets in which one or more places can hold uid rather than discrete tokens. We deene a class of uid stochastic Petri nets in such a way that the discrete and continuous portions may aaect each other. Following this deenition we provide equations for their transient and steady-state behavior. We(More)
In the scenario of a natural catastrophe or a terrorist attack, a large number of self-organizing, low-cost sensor devices can be deployed over the affected area. Each device equipped with its own power source, sensor, processing unit and low-power radio, can be imbued with the intelligence to seek out its neighbours and join in a wireless network spanning(More)
Some applications of simulation require that the model state be advanced in simulation time faster than the wall-clock time advances as the simulation executes. This faster than real-time requirement is crucial, for instance, when a simulation is used as part of a real-time control system, working through the consequences of contemplated control actions, in(More)