An Efficient Secure Route Discovery Protocol for DSR

Ensuring cryptographic integrity of the route discovery process in on demand ad hoc routing approaches like dynamic source routing (DSR) require the ability to verify that no nodes have been deleted from the path, and no node can be inserted in the path without a valid authentication. We discuss the need for early detection of inconsistencies involving inserted or deleted nodes in route request (RREQ) packets and investigate the challenges associated with catering for this requirement. We propose an efficient strategy to achieve this employing only symmetric cryptographic primitives, which is made possible due to a recently proposed multi-source broadcast encryption scheme. We outline a protocol for secure route discovery in DSR that employs such a security primitive, and provide quantitative estimates (through simulations) of gains that can be achieved by early detection of inconsistent RREQs.