Anonymous overlay network supporting authenticated routing

Typical anonymous networks mainly focus on providing strong anonymity at the price of having lower bandwidth, higher latency and degraded usability with limited routing support. They also often anonymize only a few specific applications. In this paper, we propose a new approach of constructing an anonymous network by building an overlay network atop a conventional IP network. The overlay network decouples the actual IP addresses of nodes and the virtual addresses that the nodes are using in actual applications. To do so, we use virtual addresses to anonymize the hosts and the physical IP address for efficient routing. The virtual addresses can also be dynamic for enhancing the nodes’ anonymity further. This approach also allows the network to support almost any application running on it. Together with a new anonymous routing protocol, our simulation results show that the expected latency of our proposed anonymous system can be reduced by up to 50% compared to existing systems. We also propose a suite of authentication methods which can be applied to the anonymous routing protocol we propose for preventing any malicious path cost reduction. Traditional routing protocols leak network topology information to nodes while existing anonymous routing protocols do not provide authentication for routing information. A malicious node can arbitrarily reduce the path cost value carried in an anonymous route announcement message for the purpose of negatively influencing routing efficiency or facilitating the launch of various attacks such as eavesdropping or man-in-the-middle attacks. We propose three generic schemes and several concrete instantiations to transform an anonymous routing protocol into an authenticated one which not only prevents path cost reduction attacks but also maintains anonymity. These schemes are based on three different primitives, namely one-way trapdoor functions, digital signature schemes and collision-resistant hash functions.