OpenID is an open decentralized system for single sign-on that allows users to log into multiple websites using a single digital identity. It works by allowing users to log into third-party websites using their existing account with an OpenID provider like MyOpenID or Google. When a user attempts to log into a new website, the website will contact the OpenID provider to verify the user's identity, avoiding the need for separate usernames and passwords on each individual site. OpenID is gaining popularity with thousands of websites now supporting it, including AOL, Google, and Yahoo, as it provides a more convenient login experience for users while also reducing the risks of identity theft for companies.

1. OpenID An Executive Briefing David Leip, STSM ibm.com Chief Innovation Dude & Agile Methods Advocate January 2008 This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/ or send a letter to Creative Commons, 543 Howard Street, 5th Floor, San Francisco, California, 94105, USA.

2. OpenID is a open decentralized mechanism for SSO (Single Sign-On) What is OpenID?

5. How Does it Work? Acme.com David Leip 1. David asks to log in to acme.com by giving his OpenID ex: http://leip.myopenid.com/

6. How Does it Work? Acme.com David Leip myopenid.com 2. Acme.com asks the OpenID provider (myopenid.com) to confirm that this visitor is David (the owner of this OpenID.)

7. How Does it Work? Acme.com David Leip myopenid.com 3. The OpenID provider (myopenid.com) will likely have some form of exchange with the visitor (or David), typically asking asking for a id/password, or a certificate.

8. How Does it Work? Acme.com David Leip myopenid.com 4. The OpenID provider confirms that they are satisfied, that the visitor is David.