This begs the question, "Do users really want SSO?" Unfortunately, the perception might be scarier than the reality.
"You mean, if someone knows my password they can access all my web sites?"Well... yes and no (depending on the implementation). However, the reality is that many users have the same password at all/most their sites and so the "hacker" can already get access to all their sites without SSO.
With a good Identity Provider (IdP) and strong authentication, the user should be more secure even though a single authentication event allows access to many sites. In fact, for many users, they expect this within a "proprietary" or "closed" environment ( AOL, Google, Yahoo, MSN, etc). It's extending this SSO concept beyond the "proprietary" environment that "scares" them.
Of course part of the issue is that this kind of "cross-domain" SSO doesn't really exist in the general consumer space. The unknown always breads fear; it's human nature. To overcome this "fear", we need SSO to be common place (known not unknown), and show how SSO is "just-as-secure" as the "money under the mattress" solution.
Tags: SSO, Identity, OpenID