Jamie Lewis writes about reinventing PKI in the context of federated identity.
The point here is that SAML, Liberty, and federated identity efforts are starting to define the real-world use cases for trust and authentication, something that X.509 PKI never really delivered. Without this kind of meat on the bones, PKI was a non-starter. In one sense, then, federation is an application that can leverage public key security for trust. But federation as conceived by Liberty and SAML does not require „in your face‰ PKI. Rather, it embeds public key security in the infrastructure, making it more usable. Other applications and infrastructure˜such as transaction systems and VPNs˜can also leverage embedded public key security. There is no grand „PKI in the sky‰, just sensible incremental use of public key security, which will remain a vital enabling capability.