77 research outputs found

    A secure data outsourcing scheme based on Asmuth – Bloom secret sharing

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Data outsourcing is an emerging paradigm for data management in which a database is provided as a service by third-party service providers. One of the major benefits of offering database as a service is to provide organisations, which are unable to purchase expensive hardware and software to host their databases, with efficient data storage accessible online at a cheap rate. Despite that, several issues of data confidentiality, integrity, availability and efficient indexing of users’ queries at the server side have to be addressed in the data outsourcing paradigm. Service providers have to guarantee that their clients’ data are secured against internal (insider) and external attacks. This paper briefly analyses the existing indexing schemes in data outsourcing and highlights their advantages and disadvantages. Then, this paper proposes a secure data outsourcing scheme based on Asmuth–Bloom secret sharing which tries to address the issues in data outsourcing such as data confidentiality, availability and order preservation for efficient indexing

    Review of Indexing Techniques Applied in Information Retrieval

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    Indexing is one of the important tasks of Information Retrieval that can be applied to any form of data, generated from the web, databases, etc. As the size of corpora increases, indexing becomes too time consuming and labor intensive, therefore, the introduction of computer aided indexer. A review of indexing techniques, both human and automatic indexing has been done in this paper. This paper gives an outline of the use of automatic indexing by discussing various hashing techniques including fuzzy finger printing and locality-sensitive hashing. Two different processes of matching that are used in automatic subject indexing are also reviewed. Accepting the need of automatic indexing in a possible replacement to manual indexing, studies in the development of automatic indexing tools must continu

    Privacy-Preserving Outsourced Media Search

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    International audienceThis work proposes a privacy-protection framework for an important application called outsourced media search. This scenario involves a data owner, a client, and an untrusted server, where the owner outsources a search service to the server. Due to lack of trust, the privacy of the client and the owner should be protected. The framework relies on multimedia hashing and symmetric encryption. It requires involved parties to participate in a privacy-enhancing protocol. Additional processing steps are carried out by the owner and the client: (i) before outsourcing low-level media features to the server, the owner has to one-way hash them, and partially encrypt each hash-value; (ii) the client completes the similarity search by re-ranking the most similar candidates received from the server. One-way hashing and encryption add ambiguity to data and make it difficult for the server to infer contents from database items and queries, so the privacy of both the owner and the client is enforced. The proposed framework realizes trade-offs among strength of privacy enforcement, quality of search, and complexity, because the information loss can be tuned during hashing and encryption. Extensive experiments demonstrate the effectiveness and the flexibility of the framework

    Optimizing large databases : a study on index structures

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    The following research is about comparing index structures for large databases, both analytically and experimentally. The study is divided into two main parts. The first part is centered around hash-based indexing and B-trees. Both of which are set in the context of the widely known external memory model. The second part presents the cache-oblivious model, describing its implications on the design of algorithms for any arbitrary pair of memory levels...La siguiente investigación trata sobre comparar estructuras de índice para grandes bases de datos, tanto analíticamente, como experimentalmente. El estudio se encuentra dividido en dos partes principales. La primera parte se centra en índices de hash y B-trees. Ambas estructuras son estudiadas en el contexto del modelo de acceso de disco tradicional. La segunda parte presenta al modelo cache-oblivious, incluyendo sus implicaciones en el diseño de algoritmos para niveles de memoria arbitrarios..

    Efficient and Robust Detection of Duplicate Videos in a Database

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    In this paper, the duplicate detection method is to retrieve the best matching model video for a given query video using fingerprint. We have used the Color Layout Descriptor method and Opponent Color Space to extract feature from frame and perform k-means based clustering to generate fingerprints which are further encoded by Vector Quantization. The model-to-query video distance is computed using a new distance measure to find the similarity. To perform efficient search coarse-to-fine matching scheme is used to retrieve best match. We perform experiments on query videos and real time video with an average duration of 60 sec; the duplicate video is detected with high similarity

    Qualitative Spatial Query Processing : Towards Cognitive Geographic Information Systems

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    For a long time, Geographic Information Systems (GISs) have been used by GIS-experts to perform numerous tasks including way finding, mapping, and querying geo-spatial databases. The advancement of Web 2.0 technologies and the development of mobile-based device applications present an excellent opportunity to allow the public -non-expert users- to access information of GISs. However, the interfaces of GISs were mainly designed and developed based on quantitative values of spatial databases to serve GIS-experts, whereas non-expert users usually prefer a qualitative approach to interacting with GISs. For example, humans typically resort to expressions such as the building is near a riverbank or there is a restaurant inside a park which qualitatively locate the spatial entity with respect to another. In other words, the users' interaction with current GISs is still not intuitive and not efficient. This dissertation thusly aims at enabling users to intuitively and efficiently search spatial databases of GISs by means of qualitative relations or terms such as left, north of, or inside. We use these qualitative relations to formalise so-called Qualitative Spatial Queries (QSQs). Aside from existing topological models, we integrate distance and directional qualitative models into Spatial Data-Base Management Systems (SDBMSs) to allow the qualitative and intuitive formalism of queries in GISs. Furthermore, we abstract binary Qualitative Spatial Relations (QSRs) covering the aforementioned aspects of space from the database objects. We store the abstracted QSRs in a Qualitative Spatial Layer (QSL) that we extend into current SDBMSs to avoid the additional cost of the abstraction process when dealing with every single query. Nevertheless, abstracting the QSRs of QSL results in a high space complexity in terms of qualitative representations

    A Survey Paper on Secure Privacy Preserving Structure for Content Based Information Retrieval on Large Scale

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    It is very essential to protect personal confidential data that we share or search through web. Previously there are number of privacy preserving mechanism has been developed. Here we develop a new privacy protection framework for huge- content-based information retrieval. We are offering protection in two layers. Initially, robust hash values are taken as queries to avoid revealing of unique features or content. Then, the client has to select to skip some of the bits in a hash value for increasing the confusion for the server. Since we are reducing information it is not so easy for servers to know about interest of the client. The server needs to give back the hash values of all promising candidates to the client. The client will find the best match by searching in the candidate list. Because we are only sharing hash values between server and client the privacy of client and server will be protected. We begin the idea of tunable privacy, where we can adjust level of privacy protection according to the policy. We can realized it by hash based. It can be realized through piecewise inverted indexing based on hash. We have to divide extracted feature vector into pieces and index each and every piece with a value. Every value is linked with an inverted index list. The framework has been comprehensively tested with very huge image database. We have estimated both privacy-preserving performance and retrieval performance for those content recognition application. Couple of robust hash algorithm is being used. One is based on discrete wavelet transform; the other is based on the random projections. Both of these algorithms demonstrate acceptable recital in association with state-of-the-art retrieval schemes. We believe the bulk voting attack for guesstimate the query recognition and sort. Experiment results confirm that this attack is a peril when there are near-duplicates, but the success rate is depends upon the number of distinct item and omitted bits, success rate decrees when omitted bits are increased

    TAG ME: An Accurate Name Tagging System for Web Facial Images using Search-Based Face Annotation

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    Now a day the demand of social media is increases rapidly and most of the part of social media is made up of multimedia content cognate as images, audio, video. Hence for taking this as a motivation we have proffer a framework for Name tagging or labeling For Web Facial Images, which are easily obtainable on the internet. TAG ME system does that name tagging by utilizing search-based face annotation (SBFA). Here we are going to select an image from a database which are weakly labeled on the internet and the "TAG ME" assign a correct and accurate names or tags to that facial image, for doing this a few challenges have to be faced the One exigent difficulty for search-based face annotation strategy is how to effectually conduct annotation by utilizing the list of nearly all identical face images and its labels which is weak that are habitually rowdy and deficient. In TAGME we have resolve this problem by utilizing an effectual semi supervised label refinement (SSLR) method for purify the labels of web and nonweb facial images with the help of machine learning techniques. Secondly we used convex optimization techniques to resolve learning problem and used effectual optimization algorithms to resolve the learning task which is based on the large scale integration productively. For additionally quicken the given system, finally TAGME system proposed clustering-based approximation algorithm which boost the scalability considerably
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