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A Public Key Infrastructure (PKI) is an intra- or inter-enterprise framework based on certificates to provide trust for all participating parties in such an infrastructure. As enterprises normally use software of different vendors in which each vendor product potentially builds its own software integrated stand-alone PKI the idea is to investigate possibilities to create only one enterprise wide PKI and use those certificates in all software products. After a common introduction into PKIs and potential used certificates with the primary focus on X.509v3 certificates a theoretical analysis of possible approaches to interconnect different PKIs is presented. Those results are used for the following research to establish trust relationships between the HP OpenView System Management Solution, especially its Certificate Management component, and other not HP PKI products. In addition one section covers Web Services and in particular WS-Security standards to analyze if they offer similar security mechanisms as a PKI does.

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Klaus Thonhauser has completed his diploma study "Telematics / Network Engineering" in 2003 and his subsequent part-time master study "Communication Engineering for IT" at the Carinthia University of Applied Sciences in 2007. The present paper is the outcome of his master study.

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