Adapting the Single-Request/Multiple-Response Message Exchange Pattern to Web Services

Single-Request/Multiple-Response (SRMR) is an important messaging exchange pattern because it can be used to model many real world problems elegantly. However, SRMR messaging is not directly supported by Web services, and, since it requires Callback to function it is hampered by current in-practice security schemes, such as firewalls and proxy servers. In this thesis, a framework will be proposed to support SRMR and Callback in the context of Web services and the realities of network security. The central component of the proposed solution is a Clearinghouse Web service (CWS), which serves as a communication proxy and realizes the correlation of responses with requests. One and only one CWS will be needed per enterprise that wishes to handle any number of SRMR Web services and their respective clients. Using the framework and related code generation utilities, a non-trivial case study, a Purchase Order System, has been implemented

Study, Analysis and Modeling of IP Multimedia systems on next generation networks providing mobile and fixed multimedia services

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Obligations of trust for privacy and confidentiality in distributed transactions

Purpose – This paper aims to describe a bilateral symmetric approach to authorization, privacy protection and obligation enforcement in distributed transactions. The authors introduce the concept of the obligation of trust (OoT) protocol as a privacy assurance and authorization mechanism that is built upon the XACML standard. The OoT allows two communicating parties to dynamically exchange their privacy and authorization requirements and capabilities, which the authors term a notification of obligation (NoB), as well as their commitments to fulfilling each other's requirements, which the authors term signed acceptance of obligations (SAO). The authors seek to describe some applicability of these concepts and to show how they can be integrated into distributed authorization systems for stricter privacy and confidentiality control. Design/methodology/approach – Existing access control and privacy protection systems are typically unilateral and provider-centric, in that the enterprise service provider assigns the access rights, makes the access control decisions, and determines the privacy policy. There is no negotiation between the client and the service provider about which access control or privacy policy to use. The authors adopt a symmetric, more user-centric approach to privacy protection and authorization, which treats the client and service provider as peers, in which both can stipulate their requirements and capabilities, and hence negotiate terms which are equally acceptable to both parties. Findings – The authors demonstrate how the obligation of trust protocol can be used in a number of different scenarios to improve upon the mechanisms that are currently available today. Practical implications – This approach will serve to increase trust in distributed transactions since each communicating party receives a difficult to repudiate digitally signed acceptance of obligations, in a standard language (XACML), which can be automatically enforced by their respective computing machinery. Originality/value – The paper adds to current research in trust negotiation, privacy protection and authorization by combining all three together into one set of standardized protocols. Furthermore, by providing hard to repudiate signed acceptance of obligations messages, this strengthens the legal case of the injured party should a dispute arise