Research On Tor Network Anonymity Enhancement Technology

With the rapid development of technology,the Internet has spread throughout people’s daily lives.People’s awareness of privacy protection is getting stronger and stronger,and the demand for anonymous communication is also increasing.The Tor network has the advantages of low latency and high anonymity,and has become the most popular anonymous communication network at present.However,there is currently a flood of attacks against the Tor network.The nodes of the Tor network communication link are voluntary nodes from all over the world.Attackers can analyze and modify user traffic by deploying malicious relay nodes in the Tor network or controlling the relay nodes of the Tor network,thereby causing serious damage to the anonymity of the Tor network.Discovering and eliminating these malicious relay nodes during the path-building process is an important part of enhancing the anonymity of the Tor network.This dissertation intends to strengthen the anonymity of the Tor network by studying the discovery of malicious relay nodes and the generation of anonymous links.Firstly,in view of the current Tor network marking method for malicious egress relay nodes is too simple,which leads to the problem of reduction of available nodes,a method for malicious quantification of Tor network egress relay nodes is proposed.By studying the behavior scanning technology of egress relay nodes,combined with the EWMA model,a scoring mechanism for Tor network egress relay nodes based on the reputation model is proposed.By comparing the remaining amount of egress relay nodes through simulation experiments,it is verified that the proposed method can maintain a certain scale of the egress relay nodes of the Tor network.This enhances the anonymity of the Tor network.Secondly,in view of the communication link constructed by the existing anonymous pathbuilding algorithm in the Tor network,there may be malicious relay nodes that destroy the anonymity of the Tor network,and an anonymous path-building optimization method combining the reputation of the node is proposed.By studying the construction mechanism of Tor network anonymous communication link,combined with reputation model,an anonymous path-building algorithm based on multi-dimensional evaluation of nodes is proposed.By comparing the communication time consumption and communication link anonymity with the Tor network default path-building algorithm and the path-building algorithm based on composite metrics,it is verified that the proposed algorithm can exclude malicious relay nodes from the communication link.This strengthens the anonymity of the Tor network.