Secure extension to the optimised link state routing protocol

Abstract

The design of routing protocols for mobile ad hoc networks rarely contemplates, in most cases, hostile environments. Consequently, it is common to add security extensions afterwards. One of the most important routing protocols is the optimised link state routing (OLSR), which in its specification assumes the trust of all nodes in the network, making it vulnerable to different kinds of attacks. This study presents an extension of OLSR, called COD-OLSR, which provides security for OLSR in the case of incorrect message generation attacks which can occur in two forms (identity spoofing and link spoofing). This is one of its main features, which takes into account the current topology of the node sending the message. The behaviour of COD-OLSR against different attackers in a variety of situations is evaluated. The simulation results show that COD-OLSR adds a slight overhead to OLSR and barely affects performance. The results also show that COD-OLSR is an interesting alternative to provide integrity in OLSR compared with classical mechanisms making use of cryptography, which is more complex and has a high overhead.