Taxonomy of reputation-based defending mechanisms against types of attacks in delay tolerant networks.

Delay tolerant networks (DTNs) have been standardised as a solution for wireless networking scenarios with intermittent connectivity. Limited buffer space and limited battery power in DTNs can give rise to malicious nodes. These malicious nodes misuse network resources and exhibit malicious behaviour which can cripple the network. This paper discusses various forms of malicious behaviour: flooding attack, black hole attack, and selfish attack. Several reputation based defending mechanisms against these attacks have been proposed by the DTN research community. In this paper, a taxonomy of these reputation-based defending mechanisms is defined, in terms of how reputations are calculated and disseminated. The mechanisms are categorised as source-based, peer-based, trusted-authority based or destination-based, depending on which node takes the decision to assign reputation. Under each category, the mechanisms are further classified as either node-centric (the node itself), or node-in-contact-centric (contacting node), based on which node keeps evidence of the job performed. This paper presents a review of all these reputation mechanisms and compare them in terms of computation and other parameters. Destination-based reputation mechanism seems to be a better approach.