An investigation of interoperability issues between authorisation systems within web services

The existing authorisation systems within the context of Web Services mainly apply two access control approaches – Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC). The RBAC approach links an authenticated Web Service Requester to its specific access control permission through roles, but RBAC is not flexible enough to cater for some cases where extra attribute information is needed in addition to the identity. By contrast, the ABAC approach has more flexibility, as it allows a Web Service Requester to submit necessary credentials containing extra attribute information that can fulfil the policies declared by a Web Service Provider, which aims to protect the sensitive resources/services.RBAC and ABAC can only help to establish a unilateral trust relationship between two Web Services to enable a Web Service Provider to make an access control decision. Unfortunately, the nature of Web Services presents a high probability that two Web Services may not know each other. Therefore, successful authorisation may fail, if the Web Service Requester does not trust the Web Service Provider.Trust Negotiation (TN) is also an access control approach, which can provide a bilateral trust relationship between two unknown entities, so it sometimes can enable authorisation success in situations where success is not possible through RBAC or ABAC approaches. However, interoperability issues will arise between authorisation systems within Web Services, where a bilateral trust-based authorisation solution is applied. In addition, a lack of a unified approach that can address the interoperability issues remains as a research problem. This research aims to explore possible factors causing the lack of interoperability first, and then to explore an approach that can address the interoperability issues. The main contributions of this research are an improved interoperability model illustrating interoperability issues at different layers of abstraction, and a novel interoperability-solution design along with an improved TN protocol as an example of utilising this design to provide interoperability between authorisation systems within Web Services

A semantic web service-based architecture for the interoperability of e-government services

We propose a semantically-enhanced architecture to address the issues of interoperability and service integration in e-government web information systems. An architecture for a life event portal based on Semantic Web Services (SWS) is described. The architecture includes loosely-coupled modules organized in three distinct layers: User Interaction, Middleware and Web Services. The Middleware provides the semantic infrastructure for ontologies and SWS. In particular a conceptual model for integrating domain knowledge (Life Event Ontology), application knowledge (E-government Ontology) and service description (Service Ontology) is defined. The model has been applied to a use case scenario in e-government and the results of a system prototype have been reported to demonstrate some relevant features of the proposed approach

Implementation and design of a service-based framework to integrate personal and institutional learning environments

The landscape of teaching and learning has changed in recent years because of the application of Information and Communications technology. Among the most representative innovations in this regard are Learning Management Systems. Despite of their popularity in institutional contexts and the wide set of tools and services that they provide to learners and teachers, they present several issues. Learning Management Systems are linked to an institution and a period of time, and are not adapted to learners' needs. In order to address these problems Personal Learning Environments are defined, but it is clear that these will not replace Learning Management Systems and other institutional contexts. Both types of environment should therefore coexist and interact. This paper presents a service-based framework to facilitate such interoperability. It supports the export of functionalities from the institutional to the personal environment and also the integration within the institution of learning outcomes from personal activities. In order to achieve this in a flexible, extensible and open way, web services and interoperability specifications are used. In addition some interoperability scenarios are posed. The framework has been tested in real learning contexts and the results show that interoperability is possible, and that it benefits learners, teachers and institutions.Peer ReviewedPostprint (author's final draft

A BASILar Approach for Building Web APIs on top of SPARQL Endpoints

The heterogeneity of methods and technologies to publish open data is still an issue to develop distributed systems on the Web. On the one hand, Web APIs, the most popular approach to offer data services, implement REST principles, which focus on addressing loose coupling and interoperability issues. On the other hand, Linked Data, available through SPARQL endpoints, focus on data integration between distributed data sources. The paper proposes BASIL, an approach to build Web APIs on top of SPARQL endpoints, in order to benefit of the advantages from both Web APIs and Linked Data approaches. Compared to similar solution, BASIL aims on minimising the learning curve for users to promote its adoption. The main feature of BASIL is a simple API that does not introduce new specifications, formalisms and technologies for users that belong to both Web APIs and Linked Data communities

Ontology-based semantic web services framework for knowledge management system

The latest Semantic Web developments and insights in knowledge management challenge the new era of semantic-based knowledge-management systems, where lies the new possibilities that Semantic Web affords for improved knowledge management. Connectivity and interoperability of knowledge management systems is the key to the vision of the future. We need a comprehensive framework that addresses main issues related to distributed Knowledge Management. Semantic Web Services (SWS) is the next major generation of the Web in which e-services and business communication become more knowledge-based. It proposes to extend the traditional Web Services technologies with its key enabling technologies of ontologies and semantics; to solve the problem of heterogeneity and interoperability of data across applications. This makes it possible to select, integrate and invocate services dynamically, which enable services to adapt themselves to changes without human intervention. The main purpose of this paper is to present the relevance of SWS technologies to KMS. Further, we discuss about the two major initiatives in SWS research. Later, we will propose ontology based semantic web services framework for KMS. Our focus is in the web service provider layer where we will introduce the three main components; knowledge manager, web service manager and ontology mapping manager

Implementasi Sistem Terdistribusi Berbasis Web Services (Studi Kasus : Sistem Perpustakaan dan BAA)

ABSTRAKSI: Isu besar yang dihadapi beberapa aplikasi sistem terdistribusi adalah interoperability atau kemampuan untuk beroperasi dengan aplikasi yang lain dengan perbedaan platform. Web services merupakan suatu sistem yang mendukung integrasi perbedaan platform. Web Services Description Language (WSDL) merupakan salah satu teknologi pendukung interoperabilitas dalam web services. Pembentukan WSDL harus menjamin interoperability sistem agar bisa bekerja sama dengan baik. Ada beberapa cara dalam pembentukan WSDL dalam web service. Dalam tugas akhir ini WSDL dibentuk dengan menggunakan automatic generated dari SOAP PHP. Lalu dilakukan pengujian apakah WSDL yang dibentuk memenuhi standar Basic Profile 1.2 yang merupakan standar pembentukan WSDL yang dimiliki oleh Interoperability Web Services Organisation (WS-I) dengan menggunakan interoperability testing tool. Hasilnya, WSDL yang bentuk dari automatic generatded SOAP PHP memenuhi interoperability platform dengan studi kasus pada tugas akhir ini, namun tidak memenuhi standar Basic Profile 1.2 WS-I karena dalam pembentukan dokumen WSDL terdapat 4 (empat) kesalahan, yaitu Failed, Not Applicable, Missing Input, dan Presequsite Failed. Pada tugas akhir ini, secara umum tidak terpenuhinya standar Basic Profile 1.2 tidak mempengaruhi interoperability system.Kata Kunci : interoperability, web services, sistem terdistribusi, WSDL.ABSTRACT: Major issues which faced by some of distributed systems is interoperability or the ability to operate with other applications with different platforms. Web services is a system that supports the integration of different platforms. Web Services Description Language (WSDL) is one of the supporting technologies in Web services interoperability. Establishment of WSDL should ensure the interoperability so that systems can work well together. There are several ways in the formation of the web service WSDL. In this thesis, WSDL is developed using an automatic WSDL generated from PHP SOAP. Then, based on testing whether the WSDL which was formed by automatic generated SOAP PHP meet with the Basic Profile 1.2 standard (standard that is owned by the formation of WSDL Web Services Interoperability Organisation (WS-I)) by using the interoperability testing tools. The result, a form of automatic WSDL generated PHP SOAP interoperability platform meet with a case study in this thesis, but does not meet the standards of the Basic Profile 1.2 WS-I because in the form of WSDL, there are four mistakes occurred such as Failed, Not Applicable, Missing Input and Presequsite Failed. In this thesis, in general non-fulfillment of the Basic Profile 1.2 standard does not affect the interoperability system.Keyword: interoperability, web services, distribution system, WSD

Orchestration of heterogeneous middleware services and its application to a comand and control platform

MSC Dissertation in Computer EngineeringDistributed objects was, until recently, the leading technology in the design and implementation of component-based architectures, such as the ones based on services, better known as Service-Oriented Architectures (SOA). Although established in the market for more than a decade, and therefore mature, these technologies have failed to overcome the porting of the SOA concept to the Web. Web services are a recent technology that has been growing in the last few years. Their acceptance has increased over enterprises and organizations as they seem to overcome the Web and interoperability related problems of the Distributed Objects technology. Web services provide interoperability between systems and that is undoubtedly a strength of this technology since this is a crucial aspect of nowadays business. Moreover, the widespread of services led to the recent introduction of the service composition concept, that although being a technology independent concept,is closely related to Web services and there is no tool support for other technologies. Nonetheless, distributed objects still play an important role in the development of distributed systems, namely due to performance issues that are important when it comes to the internals of a platform. However, the use of service composition in these distributed object-based platforms requires the exposure of their composing services as Web services. The main objective of this masters thesis is improve the state-of-the-art in the support for the composition of services originating from distributed objects-based platforms. Bearing in mind that these kind of platforms are composed by several services, the idea is to present a platform as a set of Web services in order to be able to orchestrate them