The purpose of this thesis is to investigate if there are environments that use some kind of central authentication system within institutions/schools. The hypothesis is that an institution not using a form of central authentication service has more need for maintenance and as such is considered a higher cost for the organization. The gathering of data has been done through interviews with technical personal at Blekinge Tekniska Högskola and Linköpings Universitet. Based on the technical background of the authors, and the system limited to discussing Windows and UNIX operating systems, a discussion and analysis of the systems working today has been done, with emphasize on the hypothesis.

Authentication services in security platforms often need to handle different types of systems which have various requirements regarding the authentication. These requirements can often interfere with each other and the issue here is that the authentication service often needs to be manually adjusted to comply with these requirements. Therefore there is a need for a flexible architectural design which enables changes and could open up for new emerging technologies and possibilities. This thesis presents an architectural design of a conformative authentication service based on SAML 2.0 to be used in security platforms. In this thesis a requirements analysis was performed and an architectural design was developed. The architectural design presented in this thesis is conformative in various aspects, e.g. usage of various authentication methods, versatile handling of attributes, handling of various SAML 2.0 profiles, possibilities to participate in various identity federations and handling of legacy systems not supporting SAML. In addition, an evaluation comparing the candidate architectural design presented in this thesis with a currently active architectural design was performed. This evaluation showed that the candidate architectural design was considered better for more usage scenarios.

Master's thesis deals with issue of cookie-based central authentication services. Present-day methods of single sign-on are described. The specification of single sign-on mechanism Cosign and its authentication filter is closely viewed. Cryptographic algorithms needed by this filter are described, as well as their possible realization in PHP. Next, the implementation of Cosign authentication filter is described. Performance of the filter is tested and its future use is analysed.