Abstract— Delay/disruption tolerant network adopts a store¬carry-and-forward mechanism, of which all the participants are assumed to cooperate with one another in message delivery, to overcome the challenges of the intermittent connection and the time-varying network topology. Unfortu¬nately, there are always some nodes deviating from the rules in order to save their own precious resources. To address the selfishness and the security problems, we propose a secure message transaction protocol for delay tolerant networks, in which the messages are encrypted by the source nodes and authorized by the TTP before they are propagated in the networks. The signatures are aggregated sequentially by the source node and the subsequent forwarders. The aggregated signatures record the message delivery paths. By checking the signatures aggregated so far, the intermediate nodes can be sure of the message authenticity and decide whether to deliver the messages to the next hops or not. Thus, the free riding attacks and path forging attacks are prevented. Furthermore, the payment mechanism of the proposed scheme makes the participants have no incentive to launch the collusion attacks in the path disclosure. In addition, the hash binary tree is harnessed to decrease the number of authorization times when fragmentation is invoked at the source, and the relationship between the delivery overhead and the authorization times is presented. In the proposed scheme, the cipher computation andbundle envelopment can be performed off-line, without the information of next hops, while the DTN nodes are driving freely without any DTN connections. Performance analysis and simulation results prove that this off-line computing design is efficient in terms of delivery ratio and delivery speed.

Index Terms— delay tolerant networks, incentive, secure, message transaction, aggregate signature

Cite:Zhongtian Jia, Lixiang Li, Zhuoran Yu, Shudong Li, and Yixian Yang, "A Secure Message Transaction Protocol for Delay Tolerant Networks," Journal of Communications, vol. 7, no.8, pp.622-633, 2012. Doi: 10.4304/jcm.7.8.622-633