Reputation aware obfuscation for mobile opportunistic networks

© 2013 IEEE. Current anonymity techniques for mobile opportunistic networks typically use obfuscation algorithms to hide node's identity behind other nodes. These algorithms are not well suited to sparse and disconnection prone networks with large number of malicious nodes and new opportunistic, adaptive. So, new, opportunistic, adaptive fully localized mechanisms are needed for improving user anonymity. This paper proposes reputation aware localized adaptive obfuscation for mobile opportunistic networks that comprises of two complementary techniques: opportunistic collaborative testing of nodes' obfuscation behaviour (OCOT) and multidimensional adaptive anonymisation (AA). OCOT-AA is driven by both explicit and implicit reputation building, complex graph connectivity analytics and obfuscation history analyses. We show that OCOT-AA is very efficient in terms of achieving high levels of node identity obfuscation and managing low delays for answering queries between sources and destinations while enabling fast detection and avoidance of malicious nodes typically within the fraction of time within the experiment duration. We perform extensive experiments to compare OCOT-AA with several other competitive and benchmark protocols and show that it outperforms them across a range of metrics over a one month real-life GPS trace. To demonstrate our proposal more clearly, we propose new metrics that include best effort biggest length and diversity of the obfuscation paths, the actual percentage of truly anonymised sources' IDs at the destinations and communication quality of service between source and destination

Evaluation of a DTN Convergence Layer for the AX.25 Network Protocol

The AX.25 Link Access Protocol for Amateur Packet Radio is a data link layer protocol derived from the ITU-T X.25 data link pro- tocol with modifications for use by amateur radio operators. One of the authors has produced a prototype AX.25 connected mode DTN Convergence Layer (CL) based on the existing DTN2 reference im- plementation. Initial testing of this implementation was undertaken on Linux in order to compare the performance of the implementa- tion with the performance of native AX.25 links. Initial results ap- pear to indicate that the current prototype can be up to 25 percent more efficient than using the Linux TCP/IP over AX.25 implemen- tation in certain circumstances. The experimental results also re- veal situations where obvious improvements can still be made to the implementation

Opportunistic Email Distribution and Access in Challenged Heterogeneous Environments

The communication paradigms for delay-tolerant networking have been modeled after email. Supporting email over DTNs in a backwards compatible manner in a heterogeneous environment has yet to be fully defined. In this paper, we present a set of conventions for and extensions to the DTNRG architecture. We have implemented a system that is able to deliver emails within a DTN network, from a DTN network to the Internet, and from the Internet to the DTN network. Our system architecture includes multiple solutions for integrating traditional and DTN-based mail delivery: DTN-based messaging clients for mobile phones and PDAs, a dedicated, standalone DTN gateway between the Internet and the DTN network, and a personal DTN mail application proxy. The latter bridges to unmodified mail user agents running on a laptop