Rolf Schillinger

A privacy-enhanced attribute-based access control system

Service-oriented architectures (SOAs) are increasingly gaining popularity due to their considerable flexibility and scalability in open IT-environments. Along with their rising acceptance comes the need for well suited security components. In this respect, access control and privacy emerged to crucial factors. Targeting the demands of a SOA, many promising authorization models have been developed, most notably the attribute-based access control (ABAC) model. In this paper we take up concepts from the OASIS XACML and WS-XACML specifications and introduce a dynamic ABAC system that incorporates privacy preferences of the service requestor in the access control process. Separating the Policy Decision Point from the service providers premises, our infrastructure enables the deployment of alternative PDPs the service requestor can choose from. We employ a PKI to reflect the sufficient trust relation between the service provider and a potential PDP. Our work is carried out within the European research project Access-eGov that aims at a European-wide e-Government service platform.

Security Requirements for a Semantic Service-oriented Architecture

Service-oriented architectures (SOAs) are a commonly used paradigm for IT infrastructures in various fields. Due to their flexibility and the easy accessibility of their underlying Web services, SOAs are the architecture of choice for more and more service providers. Semantic SOAs (SSOAs) are going one step further and are enhancing the common SOA with semantic components. However, a major success criterion of any SOA is the existence of a reliant security infrastructure. Therefore, this paper identifies security requirements for an eGovernment SSOA focusing on communication security, trust, privacy and access control. Our work is based on the architecture designed within the scope of the European research project Access-eGov, which envisions the development of a SSOA-based eGovernment platform

Building a Distributed Semantic-aware Security Architecture

Enhancing the service-oriented architecture paradigm with semantic components is a new field of research and goal of many ongoing projects. The results lead to more powerful web applications with less development effort and better user support. While some of these advantages are without doubt novel, challenges and opportunities for the security arise. In this paper we introduce a security architecture built in a semantic service-oriented architecture. Focusing on an attributebased access control approach, we present an access control model that facilitates semantic attribute matching and ontology mapping. Furthermore, our security architecture is capable of distributing the Policy Decision Point (PDP) from the service provider to different locations in the platform, eliminating the need of disclosing privacy-sensitive user attributes to the service provider. With respect to privacy preferences of the user and trust settings of the service provider, our approach allows for dynamically selecting a PDP. With more advanced trusted computing technology in the future it is possible to place the PDP on user side, reaching a maximum level of privacy.

A Semantic Security Architecture for Web Services The Access-eGov Solution

The shift from mere service-oriented architectures (SOA) to semantically enriched approaches is especially being forced in multi-domain environments that the public sector in the European Union is an example for. The security aspect is lagging behind its possibilities, and new access control approaches native to the semantic environment need to be applied. Based on architectural research work conducted within the EU-funded research project Access-eGov, we outline our implementation of a semantic security architecture for web services by using industry-standard technologies and combining them with semantic enhancements.

Analysing Requirements for Virtual Business Alliances – The Case of SPIKE

More and more companies are realising that business is best carried out in project-based virtual alliances and are intensively networking and collaborating with partner companies. This requires convergent, adaptive, and interoperable IT environments ready to support flexible, loosely coupled networked enterprises, anywhere, anytime - regardless of heterogeneous systems and applications in use. In this paper, a methodology for gathering and analysing user requirements is applied which is specifically tailored for incorporating multi-party views such as necessary for the development of collaboration platforms to support virtual alliances and to prove its significance in a real-world case study. The work presented is performed within the SPIKE project, focusing on the technical, methodological and organisational support of short-term and project-based business alliances between organisations of all types and sizes.

Detectability of Deep Packet Inspection in Common Provider/Consumer Relations

Payload examination using Deep Packet Inspection (DPI) offers (infrastructure) providers a whole new range of use cases, many of them with a potential to eavesdrop on non-public communication. Current research is almost exclusively concerned with raising this capabilities on a technological level. Critical voices about DPIs impact on the Internet with regard to privacy, net neutrality, and its other implications are raised, however often not within research communities but rather by politically interested groups. In fact, no definite method allowing detection of DPI is known. In this paper we present five different approaches targeting this problem. While starting points for DPI detection are given, including leakage of internal data or software errors, not all of of the presented approaches can be simulated or verified at all and none so far has been tested in real world settings.

Eine verteilte Autorisierungsinfrastruktur unter Berücksichtigung von Datenschutzaspekten

ZusammenfassungTraditionelle Verfahren der Rechtezuweisung (Autorisierung) und Zugriffskontrolle sind nur eingeschränkt geeignet, die Anforderungen an das Management der Nutzerprivilegien und an die Durchsetzung einer Sicherheitsstrategie in skalierbaren und hoch flexiblen verteilten Systemen umzusetzen. Dafür besser geeignet sind Sicherheitsinfrastrukturen, genauer AAIs – authentication and authorization infrastructures – und PMIs – privilege management infrastructures – die in der Lage sind, umfassende Sicherheitsdienstleistungen in einer Föderation von Systemen aus unterschiedlichen Domänen anzubieten. Dieser Beitrag enthält die Darstellung einer datenschutzorientierten AAI im Umfeld von eGovernment, die attributbasierte Zugriffskontrolle, eine XACML-Sicherheitsarchitektur zur Umsetzung und eine besondere Berücksichtigung der Datenschutzaspekte bei der Weitergabe der Nutzerattribute beinhaltet.