SecMR – a secure multipath routing protocol for ad hoc networks Rosa Mavropodi * , Panayiotis Kotzanikolaou, Christos Douligeris Department of Informatics, University of Piraeus, 80 Karaoli & Dimitriou, 18534 Piraeus, Greece Available online 28 June 2006 Abstract Multipath routing in ad hoc networks increases the resiliency against security attacks of collaborating malicious nodes, by maximizing the number of nodes that an adversary must compromise in order to take control of the communication. In this paper, we identify several attacks that render multipath routing protocols vulnerable to collaborating malicious nodes. We propose an on-demand multipath routing protocol, the secure multipath routing protocol (SecMR), and we analyze its security properties. Finally, through simulations, we evaluate the performance of the SecMR protocol in comparison with existing secure multipath routing protocols. Ó 2006 Elsevier B.V. All rights reserved. Keywords: Multipath routing protocol; Security; Collaborative attacks 1. Introduction In the mobile ad hoc network paradigm routing is a challenging task due to mobility and the result- ing inherent dynamic network topology. Moreover, the nodes in ad hoc networks are usually restricted devices in respect to their energy sources, computa- tional capabilities and communication range. Ad hoc routing protocols may be generally categorized as table driven (often called proactive) and source initiated (or on-demand). In table driven protocols (e.g. ZRP [7]), each host continuously maintains complete network routing information. On-demand schemes (e.g. DSR [10]) invoke the routing discov- ery process only on demand, in a query/reply approach. According to the number of paths that are discovered from a route request, the routing proto- cols are divided into single path (e.g. [10,21]) and multipath (e.g. [22,18]). Another feature of the rout- ing protocols is the number of the discovered paths that are actually used for sending data. Some proto- cols use only a single path for the communication, while others distribute the data through different channels. The route discovery process in the multi- path protocols may be initiated either when the active path collapses (in that case communication is performed with one of the alternative paths), or when all known paths towards the destination are broken [13]. The route discovery may stop when a sufficient number of paths are discovered or when 1570-8705/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.adhoc.2006.05.020 * Corresponding author. E-mail addresses: rosa@unipi.gr (R. Mavropodi), pkotzani@ unipi.gr (P. Kotzanikolaou), cdoulig@unipi.gr (C. Douligeris). Ad Hoc Networks 5 (2007) 87–99 www.elsevier.com/locate/adhoc