Identification And Discovery Of I2P Anonymous Communication Network

In recent years,anonymous communication technology has been developing rapidly.In general,this technology employs content encryption,multi-hop forwarding,traffic confusion and some other means to anonymize communication data and communication relationships,which makes it difficult to associate and trace anonymous communication entities.Moreover,hidden services deployed by anonymous communication technology can only be accessed through special software and configuration.As a result,a large number of hidden services form the darknet.Inundated with illegal activities including drug trafficking,arms trade,pornographic information,hacking,the darknet has seriously affected and jeopardized cyberspace security and people's daily life.Therefore,it is urgent to strengthen the supervision and governance on the darknet through technical means.The identification and discovery of anonymous communicationn network is of great significance.In terms of the current popular anonymous communication network I2 P,the supervision on I2 P cries for answers to the key technical problems including the design of the method that employes comprehensive ways and boosts robustness for large-scale discovery of anonymous node and hidden services,quick identification of I2 P traffic by protocol features,and the design of a method to locate and trace hidden services.To address these issues above,the research work of this thesis includes the following four aspects.Firstly,according to the topological features of I2 P,we design and implement an I2 P topology discovery method that integrates active replication,node awareness and node query.The number of nodes found in the experiment is over 100,000,which proves the effectiveness of the topology discovery method.Secondly,as for the loaded TCP traffic in I2 P,the features of message length sequence and message length distribution are analyzed.The classification model of machine learning is established with the traffic recognition rate over 98%,which can effectively identify the TCP traffic in I2 P.Thirdly,based on the domain name and management mechanism of I2 P hidden services,an I2 P hidden service discovery method is designed and implemented,which integrates official information acquisition,search engine information acquisition,node awareness,link expansion and so on.After a relatively long-term experiment,about 10 million darknet links and more than 150 GB hidden service data information are obtained.Furthermore,a stream-watermaing-based hidden service location is designed and employed to verify the validity of various frequency watermarking signals.Finally,according to the research results of I2 P network topology discovery,I2 P network traffic identification,I2 P hidden service discovery and location,a prototype system of I2 P anonymous communication network discovery and identification is designed and implemented,and the functions of this system are tested and verified.To sum up,this thesis studies the methods of I2 P network topology discovery,I2 P network traffic identification and I2 P hidden service discovery and location.On this basis,we implement a prototype system of I2 P anonymous communication network discovery and identification,which plays a great role in I2 P anonymous network supervision.