I hate having to build authentication structure, it creates extra code for me to write and it causes extra fuss for users in terms of the forms they have to fill out. Centralized authentication systems have long promised to get rid of this hassle. One notable examples which was never widely adopted was Microsoft’s passport. Such centralized systems allowed a system to authenticate it’s users against a central data store. To many consumers of authentication technologies having a centralized point of failure, both in terms of reliability and security was unacceptable. Especially when that centralized point of failure was Microsoft, hence Passport’s narrow adoption. Microsoft has now built a new system called Windows Live ID addressing some of Passport’s isssues.
In contrast to these centralized systems, OpenID allows a system to authenticate it’s users against any other system. I will leave an explanation of the key exchange to other sites here and here who do it much better than me. The one complexity left with the OpenID specification is that you need to remember or record an arbitrary url, which you must enter on the site you want to authenticate with. For users, this is as bad as them having to remember a password, except that the URL need not be kept secret.
The solution to this complexity comes from Clickpass. They have created a one-button graphical widget which lets users authenticate against Facebook, Google and Yahoo or any OpenID provider. The developer just has to implement a simple interface and is good to go. More importantly, the user’s experience improves dramatically since they now only have to login once with their authentication provider instead of over and over again at each site they go while repetively typing in a complex URL. So what’s not to like? Clickpass makes life easier for the developer and the user has a better experience.