Why is SharePoint 2013 adding random characters in front of usernames in Web Application Policy users?

Question

When I add a user to the Web Application Policy screen some additional random characters are added in front of the Domain.

I cannot remove the users and changing the permissions on a user with the junk characters doesn't seem to apply to the databases consistently.

These are both Service Accounts.

Answer 1

This is a claims token for Windows Authentication. SharePoint 2013, unlike 2010, uses Claims as default authentication type!

More here: http://msdn.microsoft.com/en-us/library/gg481769.aspx