The rapid growth of IP-based mobile telecommunication technologies in the past few years has revealed situations where not only a single node but an entire network moves and changes its point of attachment to the Internet. The main goal of any protocol supporting network mobility is to provide continuous, optimal and secure Internet access to all nodes and even recursively nested mobile subnetworks inside a moving network. For this purpose, the IETF (Internet Engineering Task Force) has developed the NEtwork MObility Basic Support (NEMO BS) protocol which extends the operation of Mobile IPv6 (MIPv6). In order to bypass the same problems suffered by MIPv6 and NEMO BS, a novel Host Identity Protocol (HIP) extension called HIP-NEMO is introduced, proposed and evaluated in this paper. Our proposal is based on hierarchical topology of mobile RVSs (mRVS), signaling delegation and inter-mRVS communication to enable secure and efficient network mobility support in the HIP layer. The method pro...