Resource Public Key Infrastructure (RPKI), designed to protect Internet routing from hijacks, is gaining traction: over 50% of prefixes have digital certificates, at least 27% of Autonomous Systems actively validate certificates against BGP announcements, and filter invalid routing announcements. In this study, we present the first security analysis of Krill, the only public and open-source RPKI publication point software. Publication points are hosted by the five Regional Internet Registries across the globe, or by independent Internet operators that wish to manage their own RPKI repositories.