I read an article by Rosie Lombardi in InterGovWorld that turned out not to be what I thought it was about on first reading the title "Secret identity: Solving the privacy puzzle in a federated model".
The article turned out to be a discussion not of classic web federation, but one of different approaches to using LDAP in a federated government setting. In the article, Rosie lays out the case for the copy-and-sync meta-directory approach, vs. the case for dynamic access via virtual directories. While the article was not about classic web federation using SAML or InfoCards, the article makes for a very interesting case study in federation, because the author is talking about two very different approaches using the same protocol.
Note: for those that don't know, I came to Oracle as the head of development for OctetString--a virtual directory vendor. I am obviously biased, but I hope you will see my observations are much more general than just about LDAP.
As I read the case for copy-and-sync, another article came to mind from Robin Wilton at Sun. He writes about the recent HMRC security breach in the UK where government entities were copying citizen data between departments and in the process lost one of the copies. As it turned out, their approach of copying information created huge exposure for the UK Government.
Any time entire data sets are being copied eyebrows should be raising. Instead of minimizing information usage, information was being propagated. Control was being distributed, enabling the possibility of mistakes as more systems and hands have access to valuable personal information. In fact, the people with the least control are usually the persons identified within the data -- the persons whose privacy should be protected!
On the other hand, Rosie makes a good case that when you take the minimal approach of federating information on the fly (such as with Virtual Directory), your security may be minimized to the lowest level security provider of the federation. In response, I would contend that bad data is still bad data whether it is obtained through copy-and-sync or through dynamic querying. The fault lies not with the approach but with the data itself. The protocol and approach matters little at this point, bad data is always bad data.
The positive news is that obtaining data dynamically from a provider of personal information means that data is the most current available and not dependent the frequency of the last update. Control is maintained by the information provider and each usage is auditable. Consent is also more easily verified as it is possible to check each specific use of information and whether consent is needed and obtained.
Whether the protocol used for federation was LDAP, SAML, or WS-Trust, the issues remain the same. Those building federated applications need to be able to trust their providers. They have to be able to assess the quality of their sources. There are no easy answers right now. Just as with PKI trust in the past, trusting information transferred comes down to assessing the quality of information and procedures and the quality and stability of the physical infrastructures. Liberty Alliance has launched a new initiative called the Identity Assurance Framework (IAF) where they hope to begin to solve this problem. Check it out.