119 research outputs found
Anticollusion solutions for asymmetric fingerprinting protocols based on client side embedding
In this paper, we propose two different solutions for making a recently proposed asymmetric fingerprinting protocol based on client-side embedding robust to collusion attacks. The first solution is based on projecting a client-owned random fingerprint, securely obtained through existing cryptographic protocols, using for each client a different random matrix generated by the server. The second solution consists in assigning to each client a Tardos code, which can be done using existing asymmetric protocols, and modulating such codes using a specially designed random matrix. Suitable accusation strategies are proposed for both solutions, and their performance under the averaging attack followed by the addition of Gaussian noise is analytically derived. Experimental results show that the analytical model accurately predicts the performance of a realistic system. Moreover, the results also show that the solution based on independent random projections outperforms the solution based on Tardos codes, for different choices of parameters and under different attack models
Framework for privacy-aware content distribution in peer-to- peer networks with copyright protection
The use of peer-to-peer (P2P) networks for multimedia distribution has spread out globally in recent years. This mass popularity is primarily driven by the efficient distribution of content, also giving rise to piracy and copyright infringement as well as privacy concerns. An end user (buyer) of a P2P content distribution system does not want to reveal his/her identity during a transaction with a content owner (merchant), whereas the merchant does not want the buyer to further redistribute the content illegally. Therefore, there is a strong need for content distribution mechanisms over P2P networks that do not pose security and privacy threats to copyright holders and end users, respectively. However, the current systems being developed to provide copyright and privacy protection to merchants and end users employ cryptographic mechanisms, which incur high computational and communication costs, making these systems impractical for the distribution of big files, such as music albums or movies.El uso de soluciones de igual a igual (peer-to-peer, P2P) para la distribución multimedia se ha extendido mundialmente en los últimos años. La amplia popularidad de este paradigma se debe, principalmente, a la distribución eficiente de los contenidos, pero también da lugar a la piratería, a la violación del copyright y a problemas de privacidad. Un usuario final (comprador) de un sistema de distribución de contenidos P2P no quiere revelar su identidad durante una transacción con un propietario de contenidos (comerciante), mientras que el comerciante no quiere que el comprador pueda redistribuir ilegalmente el contenido más adelante. Por lo tanto, existe una fuerte necesidad de mecanismos de distribución de contenidos por medio de redes P2P que no supongan un riesgo de seguridad y privacidad a los titulares de derechos y los usuarios finales, respectivamente. Sin embargo, los sistemas actuales que se desarrollan con el propósito de proteger el copyright y la privacidad de los comerciantes y los usuarios finales emplean mecanismos de cifrado que implican unas cargas computacionales y de comunicaciones muy elevadas que convierten a estos sistemas en poco prácticos para distribuir archivos de gran tamaño, tales como álbumes de música o películas.L'ús de solucions d'igual a igual (peer-to-peer, P2P) per a la distribució multimèdia s'ha estès mundialment els darrers anys. L'àmplia popularitat d'aquest paradigma es deu, principalment, a la distribució eficient dels continguts, però també dóna lloc a la pirateria, a la violació del copyright i a problemes de privadesa. Un usuari final (comprador) d'un sistema de distribució de continguts P2P no vol revelar la seva identitat durant una transacció amb un propietari de continguts (comerciant), mentre que el comerciant no vol que el comprador pugui redistribuir il·legalment el contingut més endavant. Per tant, hi ha una gran necessitat de mecanismes de distribució de continguts per mitjà de xarxes P2P que no comportin un risc de seguretat i privadesa als titulars de drets i els usuaris finals, respectivament. Tanmateix, els sistemes actuals que es desenvolupen amb el propòsit de protegir el copyright i la privadesa dels comerciants i els usuaris finals fan servir mecanismes d'encriptació que impliquen unes càrregues computacionals i de comunicacions molt elevades que fan aquests sistemes poc pràctics per a distribuir arxius de grans dimensions, com ara àlbums de música o pel·lícules
Multimedia
The nowadays ubiquitous and effortless digital data capture and processing capabilities offered by the majority of devices, lead to an unprecedented penetration of multimedia content in our everyday life. To make the most of this phenomenon, the rapidly increasing volume and usage of digitised content requires constant re-evaluation and adaptation of multimedia methodologies, in order to meet the relentless change of requirements from both the user and system perspectives. Advances in Multimedia provides readers with an overview of the ever-growing field of multimedia by bringing together various research studies and surveys from different subfields that point out such important aspects. Some of the main topics that this book deals with include: multimedia management in peer-to-peer structures & wireless networks, security characteristics in multimedia, semantic gap bridging for multimedia content and novel multimedia applications
Security of the Internet of Things: Vulnerabilities, Attacks and Countermeasures
Wireless Sensor Networks (WSNs) constitute one of the most promising third-millennium technologies and have wide range of applications in our surrounding environment. The reason behind the vast adoption of WSNs in various applications is that they have tremendously appealing features, e.g., low production cost, low installation cost, unattended network operation, autonomous and longtime operation. WSNs have started to merge with the Internet of Things (IoT) through the introduction of Internet access capability in sensor nodes and sensing ability in Internet-connected devices. Thereby, the IoT is providing access to huge amount of data, collected by the WSNs, over the Internet. Hence, the security of IoT should start with foremost securing WSNs ahead of the other components. However, owing to the absence of a physical line-of-defense, i.e., there is no dedicated infrastructure such as gateways to watch and observe the flowing information in the network, security of WSNs along with IoT is of a big concern to the scientific community. More specifically, for the application areas in which CIA (confidentiality, integrity, availability) has prime importance, WSNs and emerging IoT technology might constitute an open avenue for the attackers. Besides, recent integration and collaboration of WSNs with IoT will open new challenges and problems in terms of security. Hence, this would be a nightmare for the individuals using these systems as well as the security administrators who are managing those networks. Therefore, a detailed review of security attacks towards WSNs and IoT, along with the techniques for prevention, detection, and mitigation of those attacks are provided in this paper. In this text, attacks are categorized and treated into mainly two parts, most or all types of attacks towards WSNs and IoT are investigated under that umbrella: “Passive Attacks” and “Active Attacks”. Understanding these attacks and their associated defense mechanisms will help paving a secure path towards the proliferation and public acceptance of IoT technology
Steganalysis of video sequences using collusion sensitivity
In this thesis we present an effective steganalysis technique for digital video sequences
based on the collusion attack. Steganalysis is the process of detecting with a high probability
the presence of covert data in multimedia. Existing algorithms for steganalysis target
detecting covert information in still images. When applied directly to video sequences
these approaches are suboptimal. In this thesis we present methods that overcome this
limitation by using redundant information present in the temporal domain to detect covert
messages in the form of Gaussian watermarks. In particular we target the spread spectrum
steganography method because of its widespread use. Our gains are achieved by exploiting
the collusion attack that has recently been studied in the field of digital video watermarking
and more sophisticated pattern recognition tools. Through analysis and simulations we,
evaluate the effectiveness of the video steganalysis method based on averaging based collusion
scheme. Other forms of collusion attack in the form of weighted linear collusion and
block-based collusion schemes have been proposed to improve the detection performance.
The proposed steganalsyis methods were successful in detecting hidden watermarks
bearing low SNR with high accuracy. The simulation results also show the improved performance
of the proposed temporal based methods over the spatial methods. We conclude
that the essence of future video steganalysis techniques lies in the exploitation of the temporal
redundancy
Data Hiding and Its Applications
Data hiding techniques have been widely used to provide copyright protection, data integrity, covert communication, non-repudiation, and authentication, among other applications. In the context of the increased dissemination and distribution of multimedia content over the internet, data hiding methods, such as digital watermarking and steganography, are becoming increasingly relevant in providing multimedia security. The goal of this book is to focus on the improvement of data hiding algorithms and their different applications (both traditional and emerging), bringing together researchers and practitioners from different research fields, including data hiding, signal processing, cryptography, and information theory, among others
Behavior Modeling and Forensics for Multimedia Social Networks
Within the past decades, the explosive combination of multimedia
signal processing, communications and networking technologies has
facilitated the sharing of digital multimedia data and enabled
pervasive digital media distribution over all kinds of networks.
People involved in the sharing and distribution of multimedia
contents form \emph{multimedia social networks} in which users
share and exchange multimedia content, as well as other resources.
Users in a multimedia social network have different objectives and
influence each other's decision and performance. It is of ample
importance to understand how users interact with and respond to
each other and analyze the impact of human factors on multimedia
systems. This thesis illustrates various aspects of issues and
problems in multimedia social networks via two case studies of
human behavior in multimedia fingerprinting and peer-to-peer live
streaming.
Since media security and content protection is a major issue in
current multimedia systems, this thesis first studies the user
dynamics of multimedia fingerprinting social networks. We
investigate the side information which improves the
traitor-tracing performance and provide the optimal strategies for
both users (fingerprint detector and the colluders) in the
multimedia fingerprinting social network. Furthermore, before a
collusion being successfully mounted, the colluders must be
stimulated to cooperate with each other and all colluders have to
agree on the attack strategy. Therefore, not all types of
collusion are possible. We reduce the possible collusion set by
analyzing the incentives and bargaining behavior among colluders.
We show that the optimal strategies designed based on human
behavior can provide more information to the fingerprint detector
and effectively improve the collusion resistance.
The second part of this thesis focuses on understanding modelling
and analyzing user dynamics for users in various types of
peer-to-peer live streaming social networks. We stimulate user
cooperation by designing the optimal, cheat-proof, and
attack-resistant strategies for peer-to-peer live streaming social
networks over Internet as well as wireless networks. Also, as more
and more smart-phone users subscribe to the live-streaming
service, a reasonable market price has to be set to prevent the
users from reselling the live video. We start from analyzing the
equilibrium between the users who want to resell the video and the
potential buyers to provide the optimal price for the content
owner
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