1,721,147 research outputs found

    Debugging environments

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    Invariant Evaluation through Introspection for Proving Security Properties

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    Semantics-driven monitoring discovers attacks against a process by evaluating invariants on the process state. To increase the robustness and the transparency of semantics-driven monitoring, it proposes an approach that introduces two Virtual Machines (VMs) running on the same platform. One VM runs the monitored process, i.e. the process to be protected, while the other one evaluates invariants on the process state each time a process invokes a system call. The evaluation of invariant exploits an Introspection Library that enables the monitoring VM to access the memory and the processor registers of the monitored VM

    A DATA-DRIVEN SEMI-GLOBAL ALIGNMENT TECHNIQUE FOR MASQUERADE DETECTION IN STAND-ALONE AND CLOUD COMPUTING SYSTEMS Inventors: Hesham Abdelazim Ismail Mohamed KHOLIDY Fabrizio Baiardi

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    A masquerade attacker impersonates a legal user to utilize the user services and privileges. The semi-global alignment algorithm (SGA) is one of the most effective and efficient techniques to detect these attacks but it has not reached yet the accuracy and performance required by large scale, multiuser systems. To improve both the effectiveness and the performances of this algorithm, we propose the Data-Driven Semi-Global Alignment, DDSGA approach. From the security effectiveness view point, DDSGA improves the scoring systems by adopting distinct alignment parameters for each user. Furthermore, it tolerates small mutations in user command sequences by allowing small changes in the low-level representation of the commands functionality. It also adapts to changes in the user behaviour by updating the signature of a user according to its current behaviour. To optimize the runtime overhead, DDSGA minimizes the alignment overhead and parallelizes the detection and the update. After describing the DDSGA phases, we present the experimental results that show that DDSGA achieves a high hit ratio of 88.4 percent with a low false positive rate of 1.7 percent. It improves the hit ratio of the enhanced SGA by about 21.9 percent and reduces Maxion-Townsend cost by 22.5 percent. Hence, DDSGA results in improving both the hit ratio and false positive rates with an acceptable computational overhead
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