The simplest model is that an RP is a AAA client and can send the request directly to a AAA proxy. The hop-by-hop integrity protection of the AAA fabric provides technical trust. An RP can submit a request directly to the correct federation. Alternatively, a federation disambiguation fabric can be used. Such a fabric takes information about what federations the RP is part of and what federations the IdP is part of, and it routes a message to the appropriate federation. The routing of messages across the fabric, plus attributes added to requests and responses, together provide rules determination. For example, when a disambiguation fabric routes a message to a given federation, that federation's rules are chosen. Name validation is enforced as messages travel across the fabric. The entities near the RP confirm its identity and validate names it claims. The fabric routes the message towards the appropriate IdP, validating the name of the IdP in the process. The routing can be statically configured. Alternatively, a routing protocol could be developed to exchange reachability information about a given IdP and to apply policy across the AAA fabric. Such a routing protocol could flood naming constraints to the appropriate points in the fabric.