We present a unilateral authentication protocol for protecting IPv6 networks against abuse of mobile IPv6 primitives. A mobile node uses a partial hash of its public key for its IPv6 address. Our protocol integrates distribution of public keys and protects against falsification of network addresses. Our protocol is easy to implement, economic to deploy and lightweight in use. It is intended to enable experimentation with (mobile) IPv6 before the transition to a comprehensive IPSEC infrastructure.