1,024 research outputs found

    ARCHANGEL: Tamper-proofing Video Archives using Temporal Content Hashes on the Blockchain

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    We present ARCHANGEL; a novel distributed ledger based system for assuring the long-term integrity of digital video archives. First, we describe a novel deep network architecture for computing compact temporal content hashes (TCHs) from audio-visual streams with durations of minutes or hours. Our TCHs are sensitive to accidental or malicious content modification (tampering) but invariant to the codec used to encode the video. This is necessary due to the curatorial requirement for archives to format shift video over time to ensure future accessibility. Second, we describe how the TCHs (and the models used to derive them) are secured via a proof-of-authority blockchain distributed across multiple independent archives. We report on the efficacy of ARCHANGEL within the context of a trial deployment in which the national government archives of the United Kingdom, Estonia and Norway participated.Comment: Accepted to CVPR Blockchain Workshop 201

    Fast watermarking of MPEG-1/2 streams using compressed-domain perceptual embedding and a generalized correlator detector

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    A novel technique is proposed for watermarking of MPEG-1 and MPEG-2 compressed video streams. The proposed scheme is applied directly in the domain of MPEG-1 system streams and MPEG-2 program streams (multiplexed streams). Perceptual models are used during the embedding process in order to avoid degradation of the video quality. The watermark is detected without the use of the original video sequence. A modified correlation-based detector is introduced that applies nonlinear preprocessing before correlation. Experimental evaluation demonstrates that the proposed scheme is able to withstand several common attacks. The resulting watermarking system is very fast and therefore suitable for copyright protection of compressed video

    Memory Networks

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    We describe a new class of learning models called memory networks. Memory networks reason with inference components combined with a long-term memory component; they learn how to use these jointly. The long-term memory can be read and written to, with the goal of using it for prediction. We investigate these models in the context of question answering (QA) where the long-term memory effectively acts as a (dynamic) knowledge base, and the output is a textual response. We evaluate them on a large-scale QA task, and a smaller, but more complex, toy task generated from a simulated world. In the latter, we show the reasoning power of such models by chaining multiple supporting sentences to answer questions that require understanding the intension of verbs

    A Novel Approach for Preserving Privacy of Content Based Information Reterival System

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    Content based information retrieval system (CBIR) are advanced version of retrieval systems where search is based upon specific criteria in order to get relevant items. In networking environment, as search is based on content it is easy for server to know client’s interest, where client has to trust server to get relevant items. Sometimes query contains sensitive information that client does not want to reveal it, but still search should be performed. This is achieved by our proposed structure, where mainly it will deal with multimedia items such as image or audio files. In order to preserve privacy , client selects multimedia file of which hash value is generated, this value is fired towards cloud server. Cloud server contains database of stored hash values of multimedia items and based upon hamming distance and similarity search, encrypted candidate list is prepared and send it to client. Client finds best item by carrying decryption
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