This paper proposes a secure mobility support scheme for 6LoWPAN wireless sensor networks. The paper first presents the IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) architecture where the routing can be automatically performed. With the architecture, both the hierarchical Internet protocol version 6 address structure and the secure address configuration algorithm for a 6LoWPAN wireless sensor network are proposed. With the architecture and the address structure, the secure intranetwork and internetwork mobility handover algorithms are presented, and they utilize the encryption and authentication to achieve the security. During the mobility process, a mobile node does not need a care-of address, so the mobility handover process includes neither the care-of address configuration operation nor the address-binding operation. As a result, the mobility handover cost and delay are reduced. Moreover, mobile nodes do not need to be involved in the mobility handover process, so the packet loss caused by mobile nodes' failure is avoided. During the intranetwork mobility handover process, a link address is used to identify a mobile node, so the size of a control message is reduced substantially. As a result, the transmission cost and delay are reduced. The paper analyzes the performance parameters of the proposed scheme, including mobility handover cost, delay, and packet loss rate. Compared with the existing scheme without security, the proposed scheme has relatively good mobility handover performance. Copyright © 2013 John Wiley & Sons, Ltd.