You are a bank manager and you use the Internet to communicate with a group of department managers on a regular basis. You are dealing with highly confidential material and you want to exchange messages ONLY with people who are authorized by you.

Issuing an authentication certificate to a certain person will grant him or her permission to exchange messages within your closed group of managers.
Your name will appear on this person's messages as the authenticator and the other group members will be able to accept this person as a member of your closed group even if they don't know him or her.
When other people in your group click on the authenticator's name link, they will be able to see the original authentication certificate granted by you to that person.

If you choose to exchange confidential information using a bulletin board you can restrict the access to your private message board to the department managers authenticated by yourself.