Project proposal

1) In [1], the authors discussed the case when some nodes act selfish by only downloading the messages from the networks but refusing to serve as a router in order to save their own wireless network resources, like energy, storage space and computation power. To overcome this problem, the authors proposed a secure message transfer protocol with an incentive payment mechanism. The messages are encrypted by the source nodes and authorized by the third trust part before they are in the network. The source code aggregates the signatures which hold the records of the message delivery paths. With checking this aggregated information, the nodes within the sender and received can check the message authenticity and decide on delivering the message to the next node. With that way, the free riding and path forging attacks are prevented. Moreover, the payment mechanism makes the participant nodes have no incentive to launch collision attacks in the path disclosure.

2) In [2], the authors implemented a public key distribution scheme based on two-channel cryptography techniques. Different public key exchange producers implemented for between the owners and carriers. The distribution can be done when DTN nodes are within geographic range of each other. The nodes can use a manual channel to transmit verification information, and using the traditional wireless channel to transmit public key. With this technique the public key can be exchanged securely and delivered to other DTN nodes via the relay nodes as they go around. Then the authors shared an approval method for public key obtained from carriers. The authors has made the security analysis and provided that the receiver can identify who initiates the conversation and when public keys are distributed by using the two-channel technique. Also this is the first paper to design the public key distribution scheme using two-channel cryptography techniques for DTN.

3) In [3], the authors proposed a scheme called SMART for packet forwarding for DTNs. The authors also proposed two efficiency-optimization methods, via reducing the transmission and computation overhead with an aggregate signature and efficient fragmentation authentication with the Merkle Hash Tree to reduce the transmission and computation overhead. Since the DTN suffers from selfishness, this technique improves the performance of DTNs and compatible with existing routing schemes. Also, the authors showed the effectiveness of the technique with several simulations.

4) Solis et al. [4], indicated that uncontrolled messaging in ad-hoc DTN type of networks can result in unbalanced sharing of network capacity. With message fragmentation, the messages do not have higher priorities are discarded sooner, thus the delivery ratio drops significantly. Therefore, the authors investigated the impact of this problem and showed that there is a need for publicly verifiable fragment authentication mechanisms and resource management to obtain the benefits of fragmentation. In their work, the authors found out that the strong security guarantees are not required for messages conveyed by intermediate nodes in the opportunistic networking scenario.