The rapid proliferation of Internet and related technologies has created tremendous possibilities for the interoperability between domains in distributed environments. Interoperability does not come easy at it opens the way for several security and privacy breaches. In this paper, we focus on the distributed authorization discovery problem that is crucial to enable secure interoperability.??We present a distributed access path discovery framework that does not require a centralized mediator. We propose and verify a role routing protocol that propagates secure, minimal-length paths to reachable roles in other domains.??Finally, we present experimental results of our role routing protocol based on a simulation implementation.