45 research outputs found

    Environment-Sensitive Intrusion Detection

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    Abstract. We perform host-based intrusion detection by constructing a model from a program’s binary code and then restricting the program’s execution by the model. We improve the effectiveness of such model-based intrusion detection systems by incorporating into the model knowledge of the environment in which the program runs, and by increasing the accuracy of our models with a new dataflow analysis algorithm for context-sensitive recovery of static data. The environment—configuration files, command-line parameters, and environment variables—constrains acceptable process execution. Environment dependencies added to a program model update the model to the current environment at every program execution. Our new static data-flow analysis associates a program’s data flows with specific calling contexts that use the data. We use this analysis to differentiate systemcall arguments flowing from distinct call sites in the program. Using a new average reachability measure suitable for evaluation of call-stackbased program models, we demonstrate that our techniques improve the precision of several test programs ’ models from 76 % to 100%

    DDoS defense by offense

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    This article presents the design, implementation, analysis, and experimental evaluation of speak-up, a defense against application-level distributed denial-of-service (DDoS), in which attackers cripple a server by sending legitimate-looking requests that consume computational resources (e.g., CPU cycles, disk). With speak-up, a victimized server encourages all clients, resources permitting, to automatically send higher volumes of traffic. We suppose that attackers are already using most of their upload bandwidth so cannot react to the encouragement. Good clients, however, have spare upload bandwidth so can react to the encouragement with drastically higher volumes of traffic. The intended outcome of this traffic inflation is that the good clients crowd out the bad ones, thereby capturing a much larger fraction of the server's resources than before. We experiment under various conditions and find that speak-up causes the server to spend resources on a group of clients in rough proportion to their aggregate upload bandwidths, which is the intended result.National Science Foundation (U.S.) (NSF grant CNS-0225660)National Science Foundation (U.S.) (NSF grant CNS-0520241)United States. Dept. of Defense (National Security Science and Engineering Faculty Fellowship

    A Narratological Study of Robbe-Grillet's Jealousy

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    (Statement of Responsibility) by David 'Dave' Dagon(Thesis) Thesis (B.A.) -- New College of Florida, 1989RESTRICTED TO NCF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE(Bibliography) Includes bibliographical references.This bibliographic record is available under the Creative Commons CC0 public domain dedication. The New College of Florida, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.Faculty Sponsor: Hixson, Jeffre
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