Extending the security assertion markup language to support delegation for Web services and grid services

An important part of enabling the future information infrastructure is to provide convenient services for application users that make such an environment highly functional and easy to use for the non-expert. In other words, the scientist should be able to focus on the science but should have sophisticated tools at hand that enable new and enhanced modalities in which science can be performed. We describe a general architecture that provides access to scientific applications. We demonstrate how such services can interact with each other and be reused by the scientific application architect to orchestrate Grid services. Our architecture is implemented by reusing concepts, infrastructures, and middleware from Web and Grid services, as well as from the newest Globus Toolkit and the Java CoG Kit. We apply our general architecture to a specific application: Active Thermochemical Tables. This application demonstrates a number of interesting and future-oriented uses, such as the need for batch processing, interactive and collaborative steering, use of multiple platforms,visualization through large displays, and access via a portal framework. Besides the innovative use of the Grid and Web services, we also provide a novel algorithmic contribution to scientific disciplines that use thermochemical tables. Specifically, we modified the original approach to constructing thermochemical tables to include an iterative process of refinement leading to increased accuracy. We have designed a variety of access environments including a shell, a Grid desktop, and a portal for accessing the set of services provided, which include the display of network dependencies between the reactions a chemist may be interested in and interactive querying of associated species data. Modalities that need to be supported are the protection of intellectual property, the creation of metadata and information shared with and gathered by the community, and easy access to the service by the application scientists.

We present material on how to use the architectures and technologies and how to understand the specifications that are available to build a secure Web Services system. Since this technology is rapidly changing, we present the theory behind the models and explain the thinking behind many of the security specifications that are at the forefront of the technology today. Our emphasis is on showing you how to build and understand the complexities of a secure end-to-end Web Services system. This book gives you both a detailed technical understanding of the major components of an end-to-end enterprise security architecture and a broad description of how to deploy and use Web Services security technologies to protect your corporation and its interaction with the outside world.

Modern grid and Web technologies provide straightforward access to applications and services running on remote resources. The user (which may be a software developer or even an application) should be able to discover such a service and dynamically load an interface to interact with it. While some software systems support either fully or partially automatic creation of client software to access Web services, fewer support grid services in the same way. This paper introduces a new system that automatically generates client software to allow access to both grid and Web services. Although designed as a stand-alone tool for accessing any Web or grid service, we demonstrate its usefulness in the context of the SymGrid framework for grid-based symbolic computations.

The open grid services infrastructure (OGSI) defines a distributed system framework by integrating grid and Web services technologies to facilitate the sharing of various resources, which result in grid service. Grid service inherits the features from Web service, aiming at enabling interoperability among heterogeneous grid application. However, in the open grid services architecture (OGSA), grid services are isolated, it is difficult building a grid service management framework which can work across organizations. Based on BPEL4WS, this paper proposes an agent-oriented grid service modeling framework to address the difficulties in developing grid applications based on grid services.

Web services are interoperable and reusable software components that can be dynamically discovered and integrated over the Internet. Developed on open standards, Web services have become a promising solution to inter- and intra-organization application integration. The supply chain of Web services exhibits two distinct features that are not considered in previous literature on information and physical-good supply chain: the integration of multiple Web services and the cross-network externality effect between Web service vendors and users. In a quest to fill in the research gap, this paper studies the optimal pricing strategies of a monopolistic intermediary in the supply chain of complementary Web services. The Web service intermediary (WSI) provides both technical and aggregation services, and seeks to charge optimal subscription and listing fees. Analytical results show that in a supply chain of complementary Web services exhibiting cross-network effects, the optimal strategy for the WSI is to set the listing fee such that all service providers list on it. On the other hand, the optimal subscription fee depends on the intensity of the cross-network effect, consumers' valuation of value-added services, and the characteristics of the Web services under consideration.

A web service is a software system that supports interoperable machine to machine interaction over the network. It can be any kind of service provided on the web that can exchange data between applications. In simple terms, it is any program that is callable by another program across the web using standard protocols. Web services are special because they are independent of the platform, programming language, and model design. In current web applications, more businesses are gradually publishing their business as services over the web. This growing number of web services available within an organization and on the Web raises a new and challenging search problem: locating desired web services. Searching for web services with conventional web search engines is insufficient in this context. In this paper, a latent semantic web service discovery and composition framework, addressing both discovery and composition of web services, is introduced. The framework provides a graphical visualization interface that can facilitate users in finding the desired web service beyond the general keyword search and provide composition of complex services if the service does not exist. A novel approach based on an information retrieval technique known as latent semantic analysis is applied to a large web service descriptions data set collection. By using co-occurrence patterns across the entire data collection, and then using those patterns to infer semantic relationships between documents, relevant results in a ranked order can be retrieved. Moreover, a back to front algorithm is applied to the composition search interface in order to compose complex web services in full or partial terms from pre-existing web services when the requested service does not exist. An experimental study conducted on a collection of 2525 publicity available web service shows improved performance to the technique applied in obtaining much better search results.

Identity federation is a powerful scheme that links accounts of users maintained distinctly by different business partners. The concept of network identity is a driver for accelerating automation of Web Services on the Internet for users on their behalf while protecting privacy of their personally identifiable information. Although users of Web Services essentially delegate some or all privileges to an entity to perform actions, current identity based systems do not take into sufficient consideration delegation between entities hosting Web Services from a viewpoint of identity and privacy. This paper introduces a delegation model for federated identity management systems and proposes a delegation framework to provide solutions for access control in the context of delegation. The framework has a function of transferring user's privileges across the entities encoded in delegation assertion extending SAML (Security Assertion Markup Language). The framework enables users to manage their own privileges, and service providers to control access of entities based on delegated privileges by the users with assistance of a delegation authority that authorizes delegation of a delegating entity and an authentication authority that authenticates a user and manages user's name identifiers.

With the increasing use of web and Service Oriented Systems, web-services have become a widely adopted technology. Web services repositories are growing fast, creating the need for advanced tools for organizing and indexing them. Clustering web services, usually represented by Web Service Description Language (WSDL) documents, enables the web service search engines and users to organize and process large web service repositories in groups with similar functionality and characteristics. In this paper, we propose a novel technique of clustering WSDL documents. The proposed method considers web services as categorical data and each service is described by a set of values extracted from the content and structure of its description file and as quality measure of clustering is defined the mutual information of the clusters and their values. We describe the way to represent web services as categorical data and how to cluster them by using LIMBO algorithm, minimizing at the same time the information loss in features values. In experimental evaluation, our approach outperforms in terms of F-Measure the approaches which use alternative similarity measures and methods for clustering WSDL documents.

The convergence of the Semantic Web and Grid technologies has resulted in the Semantic Grid. The great effort devoted in by the Semantic Web community to achieve the semantic markup of Web services (what we call Semantic Web Services) has yielded many markup technologies and initiatives, from which the Semantic Grid technology should benefit as, in recent years, it has become Web service-oriented. Keeping this fact in mind, our first premise in this work is to reuse the ODESWS Framework for the Knowledge-based markup of Grid services. Initially ODESWS was developed to enable users to annotate, design, discover and compose Semantic Web Services at the Knowledge Level. But at present, if we want to reuse it for annotating Grid services, we should carry out a detailed study of the characteristics of Web services and Grid services and thus, we will learn where they differ and why. Only when this analysis is performed should we know how to extend our theoretical framework for describing Grid services. Finally, we present the ODESGS Framework, which is the result of having applied the extensions identified to the aforementioned Semantic Web Services description framework.

Mobile Grid, or Wireless Grid Services refers to value-added Grid Service by processing in Mobile environment. Besides Mobile Internet the traditional Internet computing is experiencing a conceptual shift from Client-Server model to Grid and Peer-to-Peer computing models. As these trends, Mobile Internet and the Grid, are likely to find each other the resource constraints that Wireless devices pose today affect the level of interoperability between them. The goal of this paper is to investigate how well the most limited Wireless devices can make use of Grid Security Services. This paper describes a novel security approach on Mobile Grid Services to validate certificate based on current Mobile XML Web Services Platform environment using XKMS (XML Key Management Specification) and SAML (Security Assertion Markup Language), XACML (extensible Access Control Markup Language) in XML Security mechanism.

While Web service models become increasingly popular and many service providers start to offer all kinds of Web services, the quality of service (QoS) for Web services has become an important factor for service requesters to consider during the selection process of appropriate Web services. In this paper, we present an evaluation and selection framework (CosmosQoS) for QoS-required Web services. A novel architecture and reputation appraisal model to monitor, store and evaluate the physical usage and post-condition of requested Web services in a requester-located network is proposed to better support service requesters such that they can select suitable Web services based on their QoS requirements, trustworthiness of Web services, and effect of network connection and configuration between service requesters and providers.

The paper has presented a resource sharing architecture for Web-Based Education based on Open Grid Services Architecture (OGSA) to integrate educational resources and improve resources utilization. Using technologies of the Grid and Web services, the architecture describes Grid services mechanism and implement scheme framework of Web-Based Education Platform. It used Web Services, AJAX and LMS API to resolve the integration and service problem in the process of application modules construction. Through integrating and managing diverse educational resources, the work in this paper provided highly efficient information service.

In 1998, Ian Foster and Carl Kesselman, together with thirty distinguished experts in high-performance computing and networking, laid the foundations of a new computing model called GRID. Their vision was introduced in the book, The GRID: Blueprint for a New Computing Infrastructure (see review, SCPE Vol. 3, No. 3 ). The editors wrote: … A computational grid is a hardware and software infrastructure that provides dependable, consistent, pervasive, and inexpensive access to high-end computational capabilities… allowing new classes of applications to emerge… as yet, we have only a preliminary understanding of what these new applications will look like. Over the next five years, Grid computing became the hottest R&D field. Academia and national labs built experimental infrastructures, new startups were established to develop Grid technologies, and the HPC giant vendors joined the party. Each one pushed in a different direction based on what and how he believed Grid computing should look. It was only a matter of time until people started to ask what the Grid is all about. A survey of ten Grid experts produced ten different answers. The question remains without a clear answer, leaving many people confused. Ian Foster picked up the gloves. In his article, What is the GRID? A three point checklist (GRIDtoday, July 22, 2002: Vol. 1, No. 6), he redefines the Grid model to reflect the trades and changes in the field during the past five years. According to Foster, a Grid is a system that: Coordinates resources that are not subject to centralized control. Uses standard, open, general-purpose protocols and interfaces. Delivers a nontrivial quality of service. But Foster's new definition could not encompass all of the Grid's approaches. Moreover, Foster explained by example what the Grid is not: A cluster management system such as Sun's Sun Grid Engine, Platform's Load Sharing Facility, or Viridian's Portable Batch System can, when installed on a parallel computer or local area network, deliver quality of service guarantees and thus constitutes a powerful Grid resource. However, such a system is not a Grid itself, due to its centralized control of the hosts that it manages Within a week the responses started to come in. The first one was from Wolfgang Gentzsch, Director of Grid computing at Sun Microsystems (GRIDtoday, August 5, 2002: Vol. 1, No. 8). Gentzsch wrote: I very much like Ian's two earlier definitions. Combined, they may provide a very generic Grid definition. The new checklist, however, reduces the potential of a wide and rich variety of Grids, with different architectures, operational models, and applications, and may miss the chance to becoming widely accepted as a standard definition of the Grid. Why do we need a definition for the Grid? Can the Grid be defined? Is a definition is necessary to the Grid's development? The Grid is an open vision and thus cannot be defined. An attempt to define the Grid can only reach the foreseen technology horizon, and this horizon is only one to two years ahead. Grid computing is a paradigm in shift. New architectures and standards are changing the shape and direction of the Grid's development. In the past year one such prominent architecture was Open Grid Services Architecture (OGSA). The OGSA is the first attempt to bridge the gap between two cyberspace worlds: the Internet and the Grid. The Internet and the Grid are two different computing models. There are people who believe that the Grid is the next generation of the Internet and the World Wide Web, saying that the Great Global Grid is still many years away. Others state that the Grid will complement, not replace, the Internet as we know it. In 1998, when the Grid blueprint was published, a new Internet language appeared called eXtensible Markup Language (XML). XML is a development tool for a new Internet computing model known as Web Services. At that time, nobody understood that there is a relationship between Web Services and the Grid. Three years past before Steve Tuecke from Argonne National Laboratory started to write a spec for Grid Services. Later, people from IBM joined the mission and together they created OGSA. The OGSA specification outlines interfaces to grid computing software that comply with Web Services standards. If adopted, Grid services such as job scheduling, authentication, failure-detection, staging of applications and data, and migration of applications and data, will all be accessed through standard Web Services architecture. OGSA is basically where Grid meets Web Services and maybe the first step towards full integration of the Internet and the Grid. The Internet appeared a decade ago. In the beginning, the Net offered primitive applications: a mailing system, ftp services, and a web of home pages. Nobody asked, What is the Internet? The years passed and new emerging Internet technologies were developed. Today we can talk on the phone over the Net, chat with friends, and video conference with colleagues on the other side of the world. New computing and business models were developed: e-commerce, e-learning, e-science, and e-you-name-it. And nobody asks what the Internet is. The Grid is a super-model, a bag of networking models associated with many types of architectures, software packages, applications, and standards. Today, when people talk about the Grid they mention Data Grids, Science Grids, and Campus Grids. And at the same time they mention Farm computing, Peer-to-peer computing, and Utility computing, among others. Ten years from now many of today's technologies will disappear and new ones will be developed. I don't know how Grid computing will look a decade from now, but I know that we will have g-commerce, g-learning, g-science, and g-chat. Nobody will ask what the Grid is. It will be obvious, just as the Internet is today. Ami Marowka The Computer Aided Design Laboratory School of Engineering and Computer Science Hebrew University of Jerusalem

The grid and Web service are converging as the WSRF is proposed. The grid not only provides the computing and resources sharing pools, but also supports the electronic business and enterprise applications integration with the composition of grid service. The paper presents a novel semantic composition method and adaptive scheduling algorithm based on grid workflow, which can benefit from the workflow architecture in the composition, visualization, verification, scheduling, execution and monitoring. The method can address semantic issues and automate the composition of grid service, and the algorithm can improve scheduling efficiency when the composite grid service is executed in the grid environment. According to the simulation experiment on the prototype implemented on the GT3, the composition and scheduling have the advantage of efficiency and effectiveness.

The advent of Web Services (WS) has signaled a true revolution in the way service-oriented computing and remote procedure invocation over the Web are conducted. Web Services comprise of a set of loosely coupled specifications to coordinate process execution from distance, based on common and widely accepted Web protocols such as HTTP, FTP, and XML, and therefore, providing increased development flexibility. Since the WS Framework was built on top of those protocols, Web Services have been widely acclaimed by the Web development community and paradoxically; they have marked one of the few examples in the history of computer protocols where a global consensus has been reached. The Web Service framework consists of essentially three basic components: 1. The Web Service Description Language (WSDL), a language that allows formal functional characterization of the provided functionalities; 2. The Simple Object Access Protocol (simply SOAP from its version 1.2), a protocol that defines the format of the information interchange; and 3. The UDDI (Universal Description, Discovery and Integration) is a catalog of Web Service descriptions. All three of these components are specified using XML markup. The elegance of the WS architecture lies in the fact that every WS transaction is taking place over established Web protocols such as HTTP and FTP. As remarked in Ballinger (2003, p. 5): “A Web Service is an application logic that is accessible using Internet standards.” This very fact has accounted for the rapid and universal adoption of Web Services. This work is organized as follows: First, a review of underlying technologies and tools is presented. Consequently, existing techniques for design methodologies are described. Next, an overview of storage and retrieval techniques for Web Services is given followed by real-world applications of Web Services. We conclude with open issues and discussion.