A link-layer authentication and key agreement scheme for mobile public hotspots in NEMO based VANET

NEMO-based VANET is a vehicular ad hoc network (VANET) with network mobility (NEMO) protocol in order to support mobile network nodes (MNNs) that are temporarily located in one vehicle and connected through a public hotspot with an Internet access. In this paper, based on certificate-less public key cryptography, a link-layer authentication and key agreement scheme, CL-AKA, is proposed. CL-AKA achieves mutual authentication between an MNN and a mobile router (MR) as well as creates a secure shared key between them. Unlike existing Wi-Fi security schemes, CL-AKA uses only one certificate verification to verify an MR to an MNN while implicitly verifying this MNN to the MR. Therefore, the proposed CL-AKA scheme has 23.76% less computation overhead than that by EAP-based WPA2 protocol, less communication overhead than that by captive portal, and higher security level than that by dummy authentication scheme. In addition, performance evaluations demonstrate that CL-AKA consumes low energy, which makes it more appropriate for implementing in less-energy mobile handhelds such as PDAs and cell phones.