A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing

Data Grids have been adopted as the platform for scientific communities that need to share, access, transport, process and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. In this paper, we discuss the key concepts behind Data Grids and compare them with other data sharing and distribution paradigms such as content delivery networks, peer-to-peer networks and distributed databases. We then provide comprehensive taxonomies that cover various aspects of architecture, data transportation, data replication and resource allocation and scheduling. Finally, we map the proposed taxonomy to various Data Grid systems not only to validate the taxonomy but also to identify areas for future exploration. Through this taxonomy, we aim to categorise existing systems to better understand their goals and their methodology. This would help evaluate their applicability for solving similar problems. This taxonomy also provides a "gap analysis" of this area through which researchers can potentially identify new issues for investigation. Finally, we hope that the proposed taxonomy and mapping also helps to provide an easy way for new practitioners to understand this complex area of research.Comment: 46 pages, 16 figures, Technical Repor

Multimedia delivery in the future internet

The term “Networked Media” implies that all kinds of media including text, image, 3D graphics, audio and video are produced, distributed, shared, managed and consumed on-line through various networks, like the Internet, Fiber, WiFi, WiMAX, GPRS, 3G and so on, in a convergent manner [1]. This white paper is the contribution of the Media Delivery Platform (MDP) cluster and aims to cover the Networked challenges of the Networked Media in the transition to the Future of the Internet. Internet has evolved and changed the way we work and live. End users of the Internet have been confronted with a bewildering range of media, services and applications and of technological innovations concerning media formats, wireless networks, terminal types and capabilities. And there is little evidence that the pace of this innovation is slowing. Today, over one billion of users access the Internet on regular basis, more than 100 million users have downloaded at least one (multi)media file and over 47 millions of them do so regularly, searching in more than 160 Exabytes1 of content. In the near future these numbers are expected to exponentially rise. It is expected that the Internet content will be increased by at least a factor of 6, rising to more than 990 Exabytes before 2012, fuelled mainly by the users themselves. Moreover, it is envisaged that in a near- to mid-term future, the Internet will provide the means to share and distribute (new) multimedia content and services with superior quality and striking flexibility, in a trusted and personalized way, improving citizens’ quality of life, working conditions, edutainment and safety. In this evolving environment, new transport protocols, new multimedia encoding schemes, cross-layer inthe network adaptation, machine-to-machine communication (including RFIDs), rich 3D content as well as community networks and the use of peer-to-peer (P2P) overlays are expected to generate new models of interaction and cooperation, and be able to support enhanced perceived quality-of-experience (PQoE) and innovative applications “on the move”, like virtual collaboration environments, personalised services/ media, virtual sport groups, on-line gaming, edutainment. In this context, the interaction with content combined with interactive/multimedia search capabilities across distributed repositories, opportunistic P2P networks and the dynamic adaptation to the characteristics of diverse mobile terminals are expected to contribute towards such a vision. Based on work that has taken place in a number of EC co-funded projects, in Framework Program 6 (FP6) and Framework Program 7 (FP7), a group of experts and technology visionaries have voluntarily contributed in this white paper aiming to describe the status, the state-of-the art, the challenges and the way ahead in the area of Content Aware media delivery platforms

Secure 3G user authentication in ad-hoc serving networks

The convergence of cellular and IP technologies has pushed the integration of 3G and WLAN networks to the forefront. With 3G networks\u27 failure to deliver feasible bandwidth to the customer and the emerging popularity, ease of use and high throughput of 802.11 WLANs, integrating secure access to 3G services from WLANs has become a primary focus. 3G user authentication initiated from WLANs has been defined by an enhancement to the extensible authentication protocol, EAP, used to transport user authentication requests over WLANs. The EAP-AKA protocol executes the 3G USIM user challenge and response authentication process over the IP backbone for WLAN serving networks. To improve the degree of control of 3G subscribers, spatial control has been proposed for 3G-WLAN user authentication. Successful execution of 3G security algorithms can be limited to a specified area by encrypting a user\u27s authentication challenge with spatial data defining his/her visited WLAN. With 3G networks\u27 limited capacity to determine a user\u27s location to the granularity of a small WLAN area and restricted access to users\u27 location due to privacy, 3G operators must rely on spatial data sent from visited WLANs to implement control for authentication. The risks of implementing EAP-AKA spatial control by 3G operators with no prior relationship or trust for serving WLAN networks are presented in this paper. An ad-hoc architecture is proposed for serving networks in 3G-WLAN integration and the advantages of this architecture that facilitate secure 3G user authentication are identified. Algorithms are proposed to define robust trust relationships between the parties in 3G-WLAN networks. The security of 3G user authentication is further protected by new mechanisms defined that are based on the quality of trust established between parties

Security plane for data authentication in information-centric networks

Orientadores: Maurício Ferreira Magalhães, Jussi KangasharjuTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: A segurança da informação é responsável pela proteção das informações contra o acesso nãoautorizado, uso, modificação ou a sua destruição. Com o objetivo de proteger os dados contra esses ataques de segurança, vários protocolos foram desenvolvidos, tais como o Internet Protocol Security (IPSEC) e o Transport Layer Security (TLS), provendo mecanismos de autenticação, integridade e confidencialidade dos dados para os usuários. Esses protocolos utilizam o endereço IP como identificador de hosts na Internet, tornando-o referência e identificador no estabelecimento de conexões seguras para a troca de dados entre aplicações na rede. Com o advento da Web e o aumento exponencial do consumo de conteúdos, como vídeos e áudios, há indícios da migração gradual do uso predominante da Internet, passando da ênfase voltada para a conexão entre hosts para uma ênfase voltada para a obtenção de conteúdo da rede, paradigma esse conhecido como information-centric networking. Nesse paradigma, usuários buscam por documentos e recursos na Internet sem se importarem com o conhecimento explícito da localização do conteúdo. Como consequência, o endereço IP que previamente era utilizado como ponto de referência do provedor de dados, torna-se meramente um identificador efêmero do local onde o conteúdo está armazenado, resultando em implicações para a autenticação correta dos dados. Nesse contexto, a simples autenticação de um endereço IP não garante a autenticidade dos dados, uma vez que o servidor identificado por um dado endereço IP não é necessariamente o endereço do produtor do conteúdo. No contexto de redes orientadas à informação, existem propostas na literatura que possibilitam a autenticação dos dados utilizando somente o conteúdo propriamente dito, como a utilização de assinaturas digitais por bloco de dado e a construção de árvores de hash sobre os blocos de dados. A ideia principal dessas abordagens é atrelar uma informação do provedor original do conteúdo nos blocos de dados transportados, por exemplo, uma assinatura digital, possibilitando a autenticação direta dos dados com o provedor, independentemente do host onde o dado foi obtido. Apesar do mecanismo citado anteriormente possibilitar tal verificação, esse procedimento é muito oneroso do ponto de vista de processamento, especialmente quando o número de blocos é grande, tornando-o inviável de ser utilizado na prática. Este trabalho propõe um novo mecanismo de autenticação utilizando árvores de hash com o objetivo de prover a autenticação dos dados de forma eficiente e explícita com o provedor original e, também, de forma independente do host onde os dados foram obtidos. Nesta tese, propomos duas técnicas de autenticação de dados baseadas em árvores de hash, chamadas de skewed hash tree (SHT) e composite hash tree (CHT), para a autenticação de dados em redes orientadas à informação. Uma vez criadas, parte dos dados de autenticação é armazenada em um plano de segurança e uma outra parte permanece acoplada ao dado propriamente dito, possibilitando a verificação baseada no conteúdo e não no host de origem. Além disso, essa tese apresenta o modelo formal, a especificação e a implementação das duas técnicas de árvore de hash para autenticação dos dados em redes de conteúdo através de um plano de segurança. Por fim, esta tese detalha a instanciação do modelo de plano de segurança proposto em dois cenários de autenticação de dados: 1) redes Peer-to-Peer e 2) autenticação paralela de dados sobre o HTTPAbstract: Information security is responsible for protecting information against unauthorized access, use, modification or destruction. In order to protect such data against security attacks, many security protocols have been developed, for example, Internet Protocol Security (IPSec) and Transport Layer Security (TLS), providing mechanisms for data authentication, integrity and confidentiality for users. These protocols use the IP address as host identifier on the Internet, making it as a reference and identifier during the establishment of secure connections for data exchange between applications on the network. With the advent of the Web and the exponential increase in content consumption (e.g., video and audio), there is an evidence of a gradual migration of the predominant usage of the Internet, moving the emphasis on the connection between hosts to the content retrieval from the network, which paradigm is known as information-centric networking. In this paradigm, users look for documents and resources on the Internet without caring about the explicit knowledge of the location of the content. As a result, the IP address that was used previously as a reference point of a data provider, becomes merely an ephemeral identifier of where the content is stored, resulting in implications for the correct authentication data. In this context, the simple authentication of an IP address does not guarantee the authenticity of the data, because a hosting server identified by a given IP address is not necessarily the same one that is producing the requested content. In the context of information-oriented networks, some proposals in the literature proposes authentication mechanisms based on the content itself, for example, digital signatures over a data block or the usage of hash trees over data blocks. The main idea of these approaches is to add some information from the original provider in the transported data blocks, for example, a digital signature, enabling data authentication directly with the original provider, regardless of the host where the data was obtained. Although the mechanism mentioned previously allows for such verification, this procedure is very costly in terms of processing, especially when the number of blocks is large, making it unfeasible in practice. This thesis proposes a new authentication mechanism using hash trees in order to provide efficient data authentication and explicitly with the original provider, and also independently of the host where the data were obtained. We propose two techniques for data authentication based on hash trees, called skewed hash tree (SHT) and composite hash tree (CHT), for data authentication in information-oriented networks. Once created, part of the authentication data is stored in a security plane and another part remains attached to the data itself, allowing for the verification based on content and not on the source host. In addition, this thesis presents the formal model, specification and implementation of two hash tree techniques for data authentication in information-centric networks through a security plane. Finally, this thesis details the instantiation of the security plane model in two scenarios of data authentication: 1) Peer-to-Peer and 2) parallel data authentication over HTTPDoutoradoEngenharia de ComputaçãoDoutor em Engenharia Elétric

Secure interoperation of wireless technologies

Tremendous emphasis has been placed on wireless technologies recently and it is expected that mobile communications will become an even bigger key driver for growth and innovation in the near future. The purpose of this paper is to study the securing, development, integration and implementation of an always on, always available, and accessible from anywhere secure wireless communication environment. Our analysis of the different wireless technologies reveals that a number of obstacles have to be managed before truly transparent wireless public data consumer offering is available. Our concern revolves around the technical development and implementation efforts of integrated wireless technologies enveloped with management processes of change and evolution. Wireless technologies have influenced our daily lives and will undoubtedly continue to play a significant role in the future. This dissertation focuses on the interoperation of wireless technologies, exploring, evaluating and presenting representations of secure, fully integrated wireless environments. The purpose is to find a cost effective, open, viable, sustainable consumer orientated high data speed offering which not only adheres to basic security requirements but surpasses it. By bringing the network to the subscriber we generate an “always-on” and “always-available” solution for data requirements fulfilling an ever increasing human demand for access to resources anywhere, anytime. A background literature of various wireless technologies, techniques and value added services is provided. An approach for the securing of critical content over wireless links in chapter seven provides a basis for access by position concepts presented in chapter eight. This secure approach to location-aware mobile access control is an essential security enhancement in the integration and interoperation models illustrated in chapter nine. These models, appropriately named SWARM 1 and SWARM 2 (System for Wireless and Roaming Mobility), illustrate different approaches to achieving a secure, fully coherent, consumer orientated, wireless data communications environment.Dissertation (MSc (Computer Science))--University of Pretoria, 2003.Computer Scienceunrestricte

Analysis domain model for shared virtual environments

The field of shared virtual environments, which also encompasses online games and social 3D environments, has a system landscape consisting of multiple solutions that share great functional overlap. However, there is little system interoperability between the different solutions. A shared virtual environment has an associated problem domain that is highly complex raising difficult challenges to the development process, starting with the architectural design of the underlying system. This paper has two main contributions. The first contribution is a broad domain analysis of shared virtual environments, which enables developers to have a better understanding of the whole rather than the part(s). The second contribution is a reference domain model for discussing and describing solutions - the Analysis Domain Model

An Emergent Architecture for Scaling Decentralized Communication Systems (DCS)

With recent technological advancements now accelerating the mobile and wireless Internet solution space, a ubiquitous computing Internet is well within the research and industrial community's design reach - a decentralized system design, which is not solely driven by static physical models and sound engineering principals, but more dynamically, perhaps sub-optimally at initial deployment and socially-influenced in its evolution. To complement today's Internet system, this thesis proposes a Decentralized Communication System (DCS) architecture with the following characteristics: flat physical topologies with numerous compute oriented and communication intensive nodes in the network with many of these nodes operating in multiple functional roles; self-organizing virtual structures formed through alternative mobility scenarios and capable of serving ad hoc networking formations; emergent operations and control with limited dependency on centralized control and management administration. Today, decentralized systems are not commercially scalable or viable for broad adoption in the same way we have to come to rely on the Internet or telephony systems. The premise in this thesis is that DCS can reach high levels of resilience, usefulness, scale that the industry has come to experience with traditional centralized systems by exploiting the following properties: (i.) network density and topological diversity; (ii.) self-organization and emergent attributes; (iii.) cooperative and dynamic infrastructure; and (iv.) node role diversity. This thesis delivers key contributions towards advancing the current state of the art in decentralized systems. First, we present the vision and a conceptual framework for DCS. Second, the thesis demonstrates that such a framework and concept architecture is feasible by prototyping a DCS platform that exhibits the above properties or minimally, demonstrates that these properties are feasible through prototyped network services. Third, this work expands on an alternative approach to network clustering using hierarchical virtual clusters (HVC) to facilitate self-organizing network structures. With increasing network complexity, decentralized systems can generally lead to unreliable and irregular service quality, especially given unpredictable node mobility and traffic dynamics. The HVC framework is an architectural strategy to address organizational disorder associated with traditional decentralized systems. The proposed HVC architecture along with the associated promotional methodology organizes distributed control and management services by leveraging alternative organizational models (e.g., peer-to-peer (P2P), centralized or tiered) in hierarchical and virtual fashion. Through simulation and analytical modeling, we demonstrate HVC efficiencies in DCS structural scalability and resilience by comparing static and dynamic HVC node configurations against traditional physical configurations based on P2P, centralized or tiered structures. Next, an emergent management architecture for DCS exploiting HVC for self-organization, introduces emergence as an operational approach to scaling DCS services for state management and policy control. In this thesis, emergence scales in hierarchical fashion using virtual clustering to create multiple tiers of local and global separation for aggregation, distribution and network control. Emergence is an architectural objective, which HVC introduces into the proposed self-management design for scaling and stability purposes. Since HVC expands the clustering model hierarchically and virtually, a clusterhead (CH) node, positioned as a proxy for a specific cluster or grouped DCS nodes, can also operate in a micro-capacity as a peer member of an organized cluster in a higher tier. As the HVC promotional process continues through the hierarchy, each tier of the hierarchy exhibits emergent behavior. With HVC as the self-organizing structural framework, a multi-tiered, emergent architecture enables the decentralized management strategy to improve scaling objectives that traditionally challenge decentralized systems. The HVC organizational concept and the emergence properties align with and the view of the human brain's neocortex layering structure of sensory storage, prediction and intelligence. It is the position in this thesis, that for DCS to scale and maintain broad stability, network control and management must strive towards an emergent or natural approach. While today's models for network control and management have proven to lack scalability and responsiveness based on pure centralized models, it is unlikely that singular organizational models can withstand the operational complexities associated with DCS. In this work, we integrate emergence and learning-based methods in a cooperative computing manner towards realizing DCS self-management. However, unlike many existing work in these areas which break down with increased network complexity and dynamics, the proposed HVC framework is utilized to offset these issues through effective separation, aggregation and asynchronous processing of both distributed state and policy. Using modeling techniques, we demonstrate that such architecture is feasible and can improve the operational robustness of DCS. The modeling emphasis focuses on demonstrating the operational advantages of an HVC-based organizational strategy for emergent management services (i.e., reachability, availability or performance). By integrating the two approaches, the DCS architecture forms a scalable system to address the challenges associated with traditional decentralized systems. The hypothesis is that the emergent management system architecture will improve the operational scaling properties of DCS-based applications and services. Additionally, we demonstrate structural flexibility of HVC as an underlying service infrastructure to build and deploy DCS applications and layered services. The modeling results demonstrate that an HVC-based emergent management and control system operationally outperforms traditional structural organizational models. In summary, this thesis brings together the above contributions towards delivering a scalable, decentralized system for Internet mobile computing and communications