Abstract
Mobile ad hoc networks (MANETs) is proposed as an extremely flexible technology for establishing wireless communications. In comparison with fixed networks or traditional mobile cellular networks, MANETs introduce some new security issues. Especially, the routing security is the most important and complicated one. In this work, we propose a two-tier authentication mechanism for MANETs. The first tier, based on hash function and the concept of MAC, provides fast message verification and group identification. The second tier, based on secret sharing technology, provides secure user identification. This two-tier authentication mechanism can prevent internal and external attacks, including black hole, impersonation, routing table overflow and energy consummation attacks. © 2004 IEEE.