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A key transport protocol based on secret sharing applications to information security

IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 2002年第4期48卷 816-824页

作者： Eskicioglu, AM Delp, EJ Purdue Univ Sch Elect & Comp Engn VIdeo & Image Proc Lab W Lafayette IN 47907 USA

Digital multimedia content is delivered to homes via the Internet, satellite, terrestrial and cable networks. Scrambling is a common approach used by conditional access systems to prevent unauthorized access to audiovisual data. The descrambling keys are securely distributed to the receivers in the same transmission channel. Their protection is an important part of the key management problem. Although public-key cryptography provides a viable solution, alternative methods are sought for economy and efficiency. Message authentication is an important objective of information security in modern electronic distribution networks. This objective is met by providing the receiver of a message an assurance of the sender's identity. As physical protection such as sealed envelopes is not possible for messages expressed as binary sequences, digital tools have been developed using cryptography. A major limitation of all cryptographic methods for message authentication lies in their use of algorithms with fixed symmetric or public keys. This paper presents a key transport protocol based on secret sharing. Conditional access and message authentication are two important application areas for which the advantages of the proposed protocol are discussed. The protocol eliminates the need for a cipher, yet effectively combines the advantages of symmetric and public-key ciphers. It can be used to build a new key management scheme that allows the service providers to generate different keys for different sets of receivers, and to renew these keys in a convenient way.

关键词： cipher conditional access content protection data integrity digital signature encryption hashing key transport message authentication multimedia public-key cryptography prepositioned secret sharing

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Limitations and requirements of content-based multimedia authentication systems

Limitations and requirements of content-based multimedia aut...

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Security and Watermarking of multimedia contents iii Conference

作者： Wu, CW IBM Corp Thomas J Watson Res Ctr Div Res Yorktown Hts NY 10598 USA

ISBN: (纸本)0819439924

Recently, a number of authentication schemes have been proposed for multimedia data such as images and sound data. They include both label based systems and semifragile watermarks. The main requirement for such authentication systems is that minor modifications such as lossy compression which do not alter the content of the data preserve the authenticity of the data, whereas modifications which do modify the content render the data not authentic. These schemes can be classified into two main classes depending on the model of image authentication they are based on. One of the purposes of this paper is to look at some of the advantages and disadvantages of these image authentication schemes and their relationship with fundamental limitations of the underlying model of image authentication. In particular, we study feature-based algorithms which generate an authentication tag based on some inherent features in the image such as the location of edges. The main disadvantage of most proposed feature-based algorithms is that similar images generate similar features, and therefore it is possible for a forger to generate dissimilar images that have the same features. On the other hand, the class of hash-based algorithms utilizes a cryptographic hash function or a digital signature scheme to reduce the data and generate an authentication tag. It inherits the security of digital signatures to thwart forgery attacks. The main disadvantage of hash-based algorithms is that the image needs to be modified in order to be made authenticatable. The amount of modification is on the order of the noise the image can tolerate before it is rendered inauthentic. The other purpose of this paper is to propose a multimedia authentication scheme which combines some of the best features of both classes of algorithms. The proposed scheme utilizes cryptographic hash functions and digital signature schemes and the data does not need to be modified in order to be made authenticatable. Several applica

关键词： data authentication cryptography digital signatures hash functions digital watermarks digital notary

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Swimmer Detection and Pose Estimation for Continuous Stroke Rate Determination

Swimmer Detection and Pose Estimation for Continuous Stroke ...

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Conference on multimedia on Mobile Devices and multimedia content access - algorithms and systems VI

作者： Zecha, Dan Greif, Thomas Lienhart, Rainer Univ Augsburg Multimedia Comp Lab Augsburg Germany

ISBN: (纸本)9780819489517

In this work we propose a novel approach to automatically detect a swimmer and estimate his/her pose continuously in order to derive an estimate of his/her stroke rate given that we observe the swimmer from the side. We divide a swimming cycle of each stroke into several intervals. Each interval represents a pose of the stroke. We use specifically trained object detectors to detect each pose of a stroke within a video and count the number of occurrences per time unit of the most distinctive poses (so-called key poses) of a stroke to continuously infer the stroke rate. We extensively evaluate the overall performance and the influence of the selected poses for all swimming styles on a data set consisting of a variety of swimmers.

关键词： Object detection pose estimation stroke rate estimation swimming channel

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Adaptive filtering for delivering multimedia services in W-CDMA cellular networks using genetic algorithms

Adaptive filtering for delivering multimedia services in W-C...

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International Conference on Wireless Networks, Communications and Mobile Computing

作者： De Angelis, F Habib, I CUNY City Coll New York NY 10031 USA

ISBN: (纸本)0780393058

This paper presents tin adaptive filtering algorithm for the delivery of multimedia content with different qualify of service (QoS) requirements in time-varying wideband code-division multiple access (W-CDMA) cellular networks. The algorithm objective is to guarantee levels of quality for two different user defined profiles (Premium, or Economy), while attempting to maximize the allocation of the radio channel bandwidth and maintaining the QoS requirements of downloaded traffic flows (audio, video, and data). Our proposed solution is based upon utilizing Genetic algorithms (GAs) to solve a multi-objective function that selects, during a control period, the bit rates and formats for the media codecs of downloaded traffic flows and assigns the air interface channel rate and power to each user, subject to different constraints. To show the performance of the algorithm, W-CDMA systems with and without filtering capabilities are compared.

关键词： adaptive filters bandwidth allocation broadband networks cellular radio code division multiple access filtering theory genetic algorithms multimedia communication quality of service QoS adaptive filtering algorithm code-division multiple access genetic a adaptive filters Code division multiple access Quality of service Genetic Algorithm (GA) multimedia services WCDMA filtering theory Broadband networks bandwidth allocation multimedia content Traffic flow audio video

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Learning approach for multi content analysis of compound images

Learning approach for multi content analysis of compound ima...

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multimedia content access: algorithms and systems iii

作者： Besnehard, Quentin Marchessoux, Cédric Kimpe, Tom Spalla, Guillaume Joubel, Arnaud Boudet, François Barco n.v. President Kennedypark 35 8500 Kortrijk Belgium IUP Génie Physiologique et Informatique University of Poitiers 40 av du Recteur Pineau 86022 Poitiers France

In the context of the European Cantata project (ITEA project, 2006-2009), within Barco, a complete Multi-content Analysis framework was developed for detection and analysis of compound images. The framework consists of: a dataset, a Multi-content Analysis (MCA) algorithm based on learning approaches, a Ground Truth, an evaluation module based on metrics and a presentation module. The aim of the MCA methodology presented here is to classify image content of computer Screenshots into different categories such as: text;Graphical User Interface;Medical images and other complex images. The AdaBoost meta-algorithm was chosen, implemented and optimized for the classification method as it fitted the constraints (real-time and precision). A large dataset separated in training and testing subsets and their ground truth (with ViPER metadata format) was both collected and generated for the four different categories. The outcome of the MCA is a cascade of strong classifiers trained and tested on the different subsets. The obtained framework and its optimization (binary search, pre-computing of the features, pre-sorting) allow to re-train the classifiers as much as needed. The preliminary results are quite encouraging with a low false positive rate and close true positive rate in comparison with expectations. The re-injection of false negative examples from new testing subsets in the training phase resulted in better performances of the MCA. © 2009 SPIE-IS&T.

关键词： Adaptive boosting

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3D content-based visualization of databases

3D content-based visualization of databases

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11th World Multi-Conference on Systemics, Cybernetics and Informatics/13th International Conference on Information systems Analysis and Synthesis

作者： Koutsoudis, Anestis Arnaoutoglou, Fotis Pavlidis, George Chamzas, Christodoulos Democritus Univ Thrace Dept Elect & Comp Engn 12 Vas Sofias Str GR-67100 Xanthi Greece Res Ctr Athena Cultural & Educ Technol Inst Xanthi 67100 Greece

ISBN: (纸本)9781934272176

The scope of this paper is to propose an innovative interactive system for 3D visualization of multimedia databases. In such databases, the digital content is accompanied by complementary information and metadata that describe the content. The proposed 3D visualization environment is able to provide multiscale representations driven by appropriate clustering processes that exploit content descriptions. It is also able to provide direct access to all the digital content, both in terms of physical access to the multimedia files as well as in terms of searching and retrieving information.

关键词： 3D graphical user interface 3D visualization content-based description content-based visualization

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Confidentiality-Preserving Image Search: A Comparative Study Between Homomorphic Encryption and Distance-Preserving Randomization

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IEEE access 2014年 2卷 125-141页

作者： Lu, Wenjun Varna, Avinash L. Wu, Min Google Mountain View CA 95014 USA Intel Corp Phoenix AZ 85226 USA Univ Maryland Dept Elect & Comp Engn College Pk MD 20742 USA Univ Maryland Inst Adv Comp Studies College Pk MD 20742 USA

Recent years have seen increasing popularity of storing and managing personal multimedia data using online services. Preserving confidentiality of online personal data while offering efficient functionalities thus becomes an important and pressing research issue. In this paper, we study the problem of content-based search of image data archived online while preserving content confidentiality. The problem has different settings from those typically considered in the secure computation literature, as it deals with data in rank-ordered search, and has a different security-efficiency requirement. Secure computation techniques, such as homomorphic encryption, can potentially be used in this application, at a cost of high computational and communication complexity. Alternatively, efficient techniques based on randomizing visual feature and search indexes have been proposed recently to enable similarity comparison between encrypted images. This paper focuses on comparing these two major paradigms of techniques, namely, homomorphic encryption based techniques and feature/index randomization-based techniques, for confidentiality-preserving image search. We develop novel and systematic metrics to quantitatively evaluate security strength in this unique type of data and applications. We compare these two paradigms of techniques in terms of their search performance, security strength, and computational efficiency. The insights obtained through this paper and comparison will help design practical algorithms appropriate for privacy-aware cloud multimedia systems.

关键词： content based image retrieval secure search secure cloud computing homomorphic encryption visual words min-hash random projection order preserving encryption

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Are accessible distance learning systems useful for all students?: Our experience with IMES, an accessible web-based learning system

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International Journal of Web-Based Learning and Teaching Technologies 2014年第1期9卷 1-17页

作者： Iglesias, Ana Moreno, Lourdes Castro, Elena Cuadra, Dolores Department of Computer Science Universidad Carlos III de Madrid Madrid Spain

Nowadays the use of distance learning systems is widely extended in engineering education. Moreover, most of them use multimedia resources that sometimes are the only educational material available to provide certain educational knowledge to the students. Unfortunately, most of the current educational systems and their educational content present accessibility barriers so some students cannot access to these educational resources. This paper introduces IMES, an inclusive system designed to ensure that students of all abilities can access the educational content of the system. But, are all the students (not only students with disabilities) satisfied with this kind of inclusive applications? Are they useful for all the students? One hundred and eight students participated in the evaluation of the system during an academic course at Universidad Carlos iii of Madrid. The evaluation shows that the system presents educational benefits to all the students in terms of usefulness and user's satisfaction.

关键词： Students

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A weight-aware recommendation algorithm for mobile multimedia systems

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MOBILE INFORMATION systems 2013年第2期9卷 139-155页

作者： Rosa, Pedro M. P. Rodrigues, Joel J. P. C. Basso, Filippo Univ Beira Interior Inst Telecomunicacoes P-6201001 Covilha Portugal

In the last years, information flood is becoming a common reality, and the general user, hit by thousands of possible interesting information, has great difficulties identifying the best ones, that can guide him in his/her daily choices, like concerts, restaurants, sport gatherings, or culture events. The current growth of mobile smartphones and tablets with embedded GPS receiver, Internet access, camera, and accelerometer offer new opportunities to mobile ubiquitous multimedia applications that helps gathering the best information out of an always growing list of possibly good ones. This paper presents a mobile recommendation system for events, based on few weighted context-awareness data-fusion algorithms to combine several multimedia sources. A demonstrative deployment were utilized relevance like location data, user habits and user sharing statistics, and data-fusion algorithms like the classical CombSUM and CombMNZ, simple, and weighted. Still, the developed methodology is generic, and can be extended to other relevance, both direct (background noise volume) and indirect (local temperature extrapolated by GPS coordinates in a Web service) and other data-fusion techniques. To experiment, demonstrate, and evaluate the performance of different algorithms, the proposed system was created and deployed into a working mobile application providing real time awareness-based information of local events and news.

关键词： Mobile computing ubiquitous computing location-aware content-aware iphone applications multimedia applications mobility

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Recognizing persons in images by learning from videos

Recognizing persons in images by learning from videos

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Conference on multimedia content access - algorithms and systems

作者： Hoerster, Eva Lux, Jochen Lienhart, Rainer Univ Augsburg Multimedia Comp Lab D-8900 Augsburg Germany

ISBN: (纸本)9780819466198

In this paper, we propose an approach for automatically, recognizing persons in images based on their general outer appearance. Therefore we build a statistical model for each person. Large amounts of training data are collected and labeled automatically by using a visual sensor array capturing image sequences containing the person to be learnt. Foreground-background segementation is performed to seperate the person from background, thus enabeling to learn the persons appearance independent of the background. Color and gradient features are extracted representing the segmented person. Person recognition of incoming photos is carried out using (k)-Nearest Neighbor(s) classification and the normalized histogram intersection match value is used as distance measure. Reported experimental results show that the presented approach performs well.

关键词： object recognition object identification person recognition person identification

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