Supported by the National Natural Science Foundation of China under Grant Nos.90104028, 90304010 (国家自然科学基金)
Rerouting is one of the main schemes used in anonymous communication systems. In some typical anonymous communication systems, data packets pass through a numbers of proxies, and then to the end receiver. So the real initiator could be concealed. However, most rerouting schemes used in some prototype systems are random schemes, which choose the forward proxy randomly among all the proxies in a system. Random rerouting scheme requires every proxy to know some information of all the proxies in the system. With systems expanding, the number of proxies in the system increases, which makes the cost for management higher. Furthermore, its expanding will increase the delay of rerouting as the distance between some of the proxies increases. The paper proposes a new rerouting scheme—short distance-prior rerouting, which implements short distance-prior forwarding, and every proxy chooses a forwarder in its nearby group. The new scheme is applied in the random probability forward rerouting and definite path length rerouting algorithms. Mathematic analysis and simulation results indicate that the new scheme can keep almost the same anonymity as the typical ones and obviously decrease the delay of forwarding. In the new scheme, each proxy only needs to know the information of proxies in its nearby group, which also gives some support to the research of scalability of anonymous systems.