Arrcus, DRL, & IIJ Research Dragon Research Labs Asia Pacific Network Information Centre In order to validate the origin Autonomous Systems (ASes) and Autonomous System relationships behind BGP announcements, routers need a simple but reliable mechanism to receive Resource Public Key Infrastructure (RFC6480) prefix origin data, Router Keys, and ASPA data from a trusted cache. This document describes a protocol to deliver them. This document describes version 2 of the RPKI-Router protocol. [RFC6810] describes version 0, and [RFC8210] describes version 1. This document is compatible with both.