This document discusses the security issues within network-layer any- cast protocols. In particular, it focuses on anycast server registra- tion with routers in an IPv6 network. Servers need to be authenti- cated and authorized to provide a particular anycast service. Clients need to be able to verify that an anycast server is authentic. While infrastructure security is the main focus of this document, we also identify the need for secure communication between anycast clients and servers.