LIP: a lightweight interlayer protocol for preventing packet injection attacks in mobile ad hoc network

Most ad hoc networks do not implement any network access control, leaving these networks vulnerable to packet injection attacks where a malicious node injects packets into the network with the goal of depleting the resources of the nodes relaying the packets. To prevent such attacks, it is necessary to employ authentication mechanisms that ensure that only authorised nodes can inject traffic into the network. We design a Lightweight Inter-layer Protocol (LIP) for preventing packet injection attacks based on an efficient local broadcast authentication mechanism. In addition to preventing attacks by unauthorised nodes, LIP can also detect and minimise the impersonation attacks by compromised nodes. Through detailed simulation study, we show that LIP is scalable, and it incurs small bandwidth overhead as well as little impact on the traffic delivery ratio even in the case of high node mobility. Moreover, the transparency and independence properties of LIP allows it to be turned on/off as desired and to be integrated seamlessly with secure routing protocols, providing stronger security services for ad hoc networks.