Confidentiality is an important requirement that restricts information sharing between multiple providers in inter-domain routing and, more generally, in any {\it Multi-Provider Distributed System (MPDS)}.However, sharing such confidential information can make these systems more robust by enabling the verification of global system invariants. For instance, undesirable interaction between intra-domain and inter-domain routing can be prevented by verifying system invariants involving confidential intra-domain information of neighboring domains. In the literature, it is generally assumed that global system invariants of MPDSs involving confidential information cannot be verified. In this paper, we demonstrate that this is {\it not true} by constructing proof-of-concept protocols that verify two such invariants relevant for robust inter-domain routing. Our work exposes a hitherto unexplored portion of MPDS design space that has the potential for making such systems more robust.