Interworking Universal Mobile Telecommunication System (UMTS) and IEEE 802.11 Wireless Local Area Networks (WLANs) introduce new challenges including the design of secured and fast handover protocols. Handover operations within and between networks must not compromise the security of the networks involved. In addition, handovers must be instantaneous to sustain the quality of service (QoS) of the applications running on the User Equipment (UE). There is a need to design fast and secured handover protocols to operate in UMTS-WLAN interworking architectures. This paper proposes two secured pre-authentication protocols in the UMTS-WLAN interworking architectures. Performance analysis of the proposed protocols show superior results in comparison to existing protocols in terms of authentication signaling cost, authentication delay and load on critical nodes involved in the authentication procedure. Additionally, the security of the proposed protocols was verified by the Automated Validation of Internet Security Protocols and Applications (AVISPA) security analyzer.