Mitigation of flooding disruption attacks in link state mobile ad hoc networks

The Optimized Link State Routing (OLSR) is a proactive link state routing protocol, designed exclusively for Mobile Ad Hoc Networks (MANETs). OLSR is based on the selection of Multipoint Relays (MPRs) as a mechanism to reduce the size and number of control traffic messages flooded in the network. OLSR is not secure by design. A misbehaving node can affect the topology map acquisition process by interrupting the flooding of control information or disturbing the MPR selection process. This kind of attacks can be carried out in networks with cryptographic capabilities. OLSR is defined in RFC3626 and considers the selection of MPRs with additional coverage to increase the amount of reported information. Nevertheless, the overhead of the network increases due to the added number of control traffic messages. We propose a k-robust-MPR selection. Every node selects, when possible, k + 1 disjoint MPR sets. The union of those sets, is a k -robust-MPR set. Our k-robust-MPR selection mitigates the effect of control traffic attacks and reduces the overhead generated by redundant control messages. Hierarchical OLSR (HOLSR) has been proposed to address scalability in MANETs. HOLSR implements the MPR flooding mechanism for infra-cluster and inter-cluster communications. We implement our k-robust-MPR selection to mitigate the effect of flooding disruption attacks at any hierarchical level. HOLSR implements Cluster ID Announcement (CID) messages to organize the network in clusters. We propose algorithm Hash-Chained_CID_Dissemination (HCCD) to detect and discard invalid CID messages. Multipath OLSR (MP-OLSR) is proposed to increase the resilience against failures in MANETs. Besides the effect of flooding disruption attacks, in MP-OLSR, nodes obtain only partial link-state information. MP-OLSR proposes control traffic messages with redundant information to construct disjoint paths. However, this increases considerably the size of the messages. We propose a Disjoint Multipath OLSR (DM-OLSR) strategy to construct, when possible, t+1 strictly disjoint paths. DM-OLSR relies on the k-Robust-MPR selection to enhance the network topology view and the route computation phases.