> Using a CDN that will let you “tag” resources and conditionally provide access based on whether HTTP headers match those tags, you issue tokens to clients an

> Using a CDN that will let you “tag” resources and conditionally provide access based on whether HTTP headers match those tags, you issue tokens to clients and add or remove tags to give and revoke access. The tokens are the resource. Your auth is what tags the tokens. Your auth is the only entity that is able to compute the tags that would match the criteria of the tokens to invalidate them.