Routing is a critical function in multi-hop mobile ad hoc networks (MANETs). A number of MANET-oriented routing protocols have been proposed, of which DSR is widely considered both the simplest and the most effective. At the same time, security in MANETs – especially, routing security – presents a number of new and interesting challenges. Many security techniques geared for MANETs have been developed, among which Ariadne is the flagship protocol for securing DSR. The focus of this work is on securing the Route Discovery process in DSR. Our goal is to explore a range of suitable cryptographic techniques with varying flavors of security, efficiency and robustness. The Ariadne approach, while very efficient, assumes loose time synchronization among MANET nodes and does not offer non-repudiation. If the former is not possible or the latter is desired, an alternative approach is necessary. To this end, we construct a Secure Route Discovery protocol (SRDP) which allows the source to...