Mobile IP gets its firm position as a layer-3 mobility protocol for the 3rd generation and beyond the 3rd generation communication system. Nevertheless, due to the security defects caused by adapting MIP for real service, several systems such as AAA infrastructure have been introduced. On the other hand, PKI infrastructure is considered to be a core standard infrastructure to handle the authentication and secure channel for the present and future network. In this paper, we suggest a secure registration scheme with authentication using PKI infrastructure. Suggested scheme produces less static key management overhead compared with legacy scheme and supports the previously deployed standard authentication infrastructure. Especially, it has a feature that supports mobile communication system. Secure re-distribution of dynamic session key using asymmetric key and the optimized authentication roundtrip time for handoffs shows such a feature.