Wireless technologies such as the Wireless Local Area Network (WLAN), the Worldwide Interoperability for Microwave Access (WiMAX), and the Third-Generation (3G) mobile communications system complement each other to support a variety of services suited for the home, urban, and global environments. As roaming users expect a seamless handover (HO) experience when switching from one wireless network to another, fast and secure HO operations must be supported by the networks. In this paper, we present and analyze five reauthentication protocols for HOs between WiMAX and WLANs by subscribers of networks conforming to the 3G Partnership Project (3GPP) standards. Our proposed protocols achieve outstanding performance results compared to standard protocols in terms of reauthentication signaling traffic and reauthentication delay, while fulfilling essential HO security requirements such as the provision of mutual authentication and forward and backward secrecy.