OpenID (www.openid.net) is a single sign-on mechanism that has recently become popular. For the average user, the benefit of OpenID is that it will let you use the same username and password at any new web site you visit instead of having to sign-up using a new username and password each time. Although this seems to be a great idea, relatively few users have OpenID credentials, and so OpenID is still untested. This panel looks critically at OpenID and its potential security and privacy concerns. The panel may also discuss related solutions such as oAuth (www.oauth.net).