关键词: 匿名通信, Crowds, 前驱攻击

Abstract: In Crowds，an anonymous browsing system，on the premise of having slight effect on the level of anonymity degree，improves the system performance by decreasing forwarding probability to reduce the length of rerouting paths.This paper proposes a method to confirm the decreasing proportion quotiety using the discipline that the expected length of a path descending.Simulation result shows that the method can improve effectively the performance with reducing the length of rerouting path，while keep the anonymity at the same level.

Key words: anonymous communication, Crowds, predecessor attack