Systems and techniques for routing and application domain security are described. A described technique includes receiving, at an internal ingress port of a router of a first chip, a first processing packet that includes a first destination identifier from a computing resource of the first chip; obtaining a first source identifier from the first chip's secured register; and routing the first processing packet to a first egress port of the router based on a determination that the first source identifier and the first destination identifier are a first authorized communication pair. The technique can include receiving, at the router's external ingress port, a transport packet, that includes a second source identifier and a second processing packet, from a second chip coupled with the first chip; and performing an authorization process based on the second source identifier and a second destination identifier before routing the second processing packet.
