212,900 research outputs found

    Universal Short-Circuit and Open-Circuit Fault Detection for an Inverter

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    Short-circuit and open-circuit faults of an inverter’s power device often lead to catastrophic failure of the entire system if not detected and acted upon within a few microseconds, particularly for emerging wide bandgap (WGB) power semiconductors. While a significant amount of research has been done on the fast and accurate protection and detection of short-circuit faults, there has been less success corresponding to the research on open-circuit faults. Common downfalls include protection and detection that are too application-specific, take longer than a couple of microseconds, and are not cost-efficient. This study proposes a new open-circuit fault protection and detection system integrated with a pre-existing short-circuit system called desaturation protection. First, a literature review is conducted to confirm the necessity of the new protection and detection scheme. Second, the operation principle of the newly proposed protection and detection circuitry is discussed, and design considerations are given. Third, a comprehensive case study revolving around implementing the new protection and detection system is conducted using Synopsys/Saber simulation software. Fourth, an experiment is devised and constructed to showcase the protection and detection scheme’s success, effectiveness, and adaptability in a real-world environment. Fifth, concluding remarks are given, summarizing all the work presented in this study. The results of testing the proposed system illustrate the success and reliability of the new fault protection and detection system

    Study on seam carving for image fingerprint

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    In past several years many image contents are distributed via internet. But illegal copy problem are rise up. Multimedia fingerprint techniques are tools for resist illegal copy. However today collusion attack such as average attack is appeared. Collusion attack is efficient method for breaking copyright protection scheme of image fingerprint. This paper presented an image fingerprint scheme to resistant collusion attack which is average attack especially. Proposed image fingerprint scheme is applied seam carving technique. Experimental results show that proposed image fingerprint scheme was good performance.2012 6th International Conference on Complex, Intelligent, and Software Intensive Systems, CISIS 2012;Palermo;4 July 2012through6 July 201

    Transparent code authentication at the processor level

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    The authors present a lightweight authentication mechanism that verifies the authenticity of code and thereby addresses the virus and malicious code problems at the hardware level eliminating the need for trusted extensions in the operating system. The technique proposed tightly integrates the authentication mechanism into the processor core. The authentication latency is hidden behind the memory access latency, thereby allowing seamless on-the-fly authentication of instructions. In addition, the proposed authentication method supports seamless encryption of code (and static data). Consequently, while providing the software users with assurance for authenticity of programs executing on their hardware, the proposed technique also protects the software manufacturers’ intellectual property through encryption. The performance analysis shows that, under mild assumptions, the presented technique introduces negligible overhead for even moderate cache sizes

    Havens: Explicit Reliable Memory Regions for HPC Applications

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    Supporting error resilience in future exascale-class supercomputing systems is a critical challenge. Due to transistor scaling trends and increasing memory density, scientific simulations are expected to experience more interruptions caused by transient errors in the system memory. Existing hardware-based detection and recovery techniques will be inadequate to manage the presence of high memory fault rates. In this paper we propose a partial memory protection scheme based on region-based memory management. We define the concept of regions called havens that provide fault protection for program objects. We provide reliability for the regions through a software-based parity protection mechanism. Our approach enables critical program objects to be placed in these havens. The fault coverage provided by our approach is application agnostic, unlike algorithm-based fault tolerance techniques.Comment: 2016 IEEE High Performance Extreme Computing Conference (HPEC '16), September 2016, Waltham, MA, US

    LightBox: Full-stack Protected Stateful Middlebox at Lightning Speed

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    Running off-site software middleboxes at third-party service providers has been a popular practice. However, routing large volumes of raw traffic, which may carry sensitive information, to a remote site for processing raises severe security concerns. Prior solutions often abstract away important factors pertinent to real-world deployment. In particular, they overlook the significance of metadata protection and stateful processing. Unprotected traffic metadata like low-level headers, size and count, can be exploited to learn supposedly encrypted application contents. Meanwhile, tracking the states of 100,000s of flows concurrently is often indispensable in production-level middleboxes deployed at real networks. We present LightBox, the first system that can drive off-site middleboxes at near-native speed with stateful processing and the most comprehensive protection to date. Built upon commodity trusted hardware, Intel SGX, LightBox is the product of our systematic investigation of how to overcome the inherent limitations of secure enclaves using domain knowledge and customization. First, we introduce an elegant virtual network interface that allows convenient access to fully protected packets at line rate without leaving the enclave, as if from the trusted source network. Second, we provide complete flow state management for efficient stateful processing, by tailoring a set of data structures and algorithms optimized for the highly constrained enclave space. Extensive evaluations demonstrate that LightBox, with all security benefits, can achieve 10Gbps packet I/O, and that with case studies on three stateful middleboxes, it can operate at near-native speed.Comment: Accepted at ACM CCS 201
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