The Host Identity Indirection Infrastructure (Hi3) is a networking architecture for mobile hosts, derived from the Internet Indirection Infrastructure (i3) and the Host Identity Protocol (HIP). Hi3 has efficient support for secure mobility and multihoming, which both are crucial for future Internet applications. In this paper, we describe and analyze Hi3 in detail. Compared to existing solutions, Hi3 achieves better resilience, scalability and security. Both our analysis and early measurements support the notion that Hi3 preserves the best of both approaches while improving performance compared to i3 and enhancing flexibility and security compared to HIP.