Security is one of the most important requirements to make a software system running in the cloud acceptable for the intended user community. This is especially true in times like this where people’s privacy is under attack on a daily basis. Just follow the news in Germany. It’s a big concern and not far fetched, not at all.
Computer security got a couple of basic pillars; Identity Management is one of them. In the new realm of cloud computing, this comes along with authentication and authorization in distributed systems. SAML (the SAML 2.0 protocol) and OpenID are more or less standards to support the implementation, also in terms of interoperability. Big vendor’s cloud architectures (just see the Geneva project as an example) do support these standards. This is not just a good approach in terms of interoperability; it also leads to a better understanding and visibility regarding the underlying implementation and infrastructure which probably leads to more trust and better acceptance.