Deciding Your Own Anonymity: User-Oriented Node Selection in I2P

With the development of Internet applications, anonymous communication technology plays a very significant role in protecting personal privacy. As one of the most popular anonymous communication systems, I2P provides strong anonymity through its encryption and communication schemes. However, I2P does not consider the users' preferences, which is difficult to meet the individual demands of specific users and then allows them to decide their anonymity. Thus, this paper proposes two novel user-oriented node selection algorithms that can effectively enhance the anonymity or reduce the communication delay over the I2P network. In order to choose proper nodes, we also investigate key factors to evaluate the nodes. Then, the basic node selection algorithm (BNSA) is proposed to group routing nodes and provide high-performance node candidates. Based on BNSA, the geographic-diversity-oriented node selection algorithm (GDNSA) and the communication-delay-oriented node selection algorithm (CDNSA) are proposed. These can improve the anonymity or communication performance of the I2P network. The GDNSA increases the attack difficulty by establishing tunnels that span multiple regions. In the meantime, the CDNSA reduces the communication delay of the tunnel by selecting the next hop node with the lowest communication delay. Finally, the mathematical analysis and experimental results show that the GDNSA has good resistance to collusion attacks, and the CDNSA reduces the communication delay in spite of weakening a little anonymity.