دانلود رایگان مقاله PrivHab +: یک پروتکل مسیریابی جغرافیایی امن برای DTN

Abstract

We present PrivHab+, a secure geographic routing protocol that learns about the mobility habits of the nodes of the network and uses this information in a secure manner. PrivHab+ is designed to operate in areas that lack of network, using the store-carry-and-forward approach. PrivHab+ compares nodes and chooses the best choice to carry messages towards a known geographical location. To achieve a high performance and low overhead, PrivHab+ uses information about the usual whereabouts of the nodes to make optimal routing decisions. PrivHab+ makes use of cryptographic techniques from secure multi-party computation to preserve nodes’ privacy while taking routing decisions. The overhead introduced by PrivHab+ is evaluated using a proof-of-concept implementation, and its performance is studied under the scope of a realistic application of podcast distribution. PrivHab+ is compared, through simulation, with a set of well-known delay-tolerant routing algorithms in two different scenarios of remote rural areas.

8. Conclusions

We have defined an elliptic model of habitat. The habitat models node’s whereabouts based on the idea of exploiting life-cycles. The habitat is useful to compare the intermediate nodes to decide who is a better choice to carry each message towards its destination. We have presented PrivHab+, a secure geographical DTN routing protocol that uses the habitat to make routing decisions. PrivHab+ takes advantage of Taxicab geometry and makes use of homomorphic cryptography techniques to preserve the privacy of the participants while comparing the habitats of the candidate nodes. PrivHab+ has been analysed as a secure multi-party computation to proof that the protocol is secure. The only knowledge that can be learned by each participant about others intimacy is the same that could be inferred from the output of the protocol. This is an important point that makes PrivHab+ recommendable to use in scenarios where nodes are so related, directly or indirectly, to a person that their privacy needs to be protected. We have developed a proof-of-concept implementation that demonstrates that the presented protocol is viable and that it can be executed on small devices with a good performance. Both the computation and the communication overhead introduced by PrivHab+ is proven to be affordable and to not degrade the performance of the network. Besides, simulations based on two podcast distribution scenarios have shown that PrivHab+ performs better than a set of well known DTN routing protocols and minimises the network overhead. The qualitative comparison between PrivHab+ and the other routing protocols shows that PrivHab+ is a good choice not only for this two scenarios. In fact, PrivHab+ is a good choice in any DTN scenario where nodes are linked to people, where mobility patterns are routinary, and where the considered distances are high, forcing the need of lots of hops to reach each destination. As future lines of research, we plan to study the impact of different forwarding policies on the performance of PrivHab+, to improve the elliptic model of habitat using a more complex representation, that does not have to be necessarily a geometric figure, and to develop an enhanced version of PrivHab+ that compares simultaneously three or more habitats. We also plan to study the performance of PrivHab+ in different scenarios and to present more real applications that could benefit from this secure geographic routing protocol.