Many boundaries impede the flow of authorization information, forcing applications that span those boundaries into hop-by-hop approaches to authorization. We present a unified approach to authorization. Our approach allows applications that span administrative, network, abstraction, and protocol boundaries to understand the end-to-end authority that justifies any given request. The resulting distributed systems are more secure and easier to audit.

We describe boundaries that can interfere with end-to-end authorization, and outline our unified approach. We describe the system we built and the applications we adapted to use our unified authorization system, and measure its costs. We conclude that our system is a practical approach to the desirable goal of end-to-end authorization.