Tor Network Data Analysis And Improvement And Implementation Of Tor Routing Algorithm

The Second Generation Onion Router(Tor)system is one of the most popular anonymous communication systems and has the largest anonymous communication user group.The routing algorithm in Tor directly affects the anonymity,security,and transmission rate of the communication circuit.However,there are drawbacks in the design of the Tor algorithm.This paper conducts research work on the shortage of Tor network.This paper expounds the basic principle of Tor system,collects the historical data of Tor network,through multi-angle processing and analysis of Tor network data,compares the consistency and differences between Tor's ideal routing node selection model and actual routing node selection model.Based on this,against the shortcomings of Tor's bandwidth-based routing algorithm in security and transmission efficiency,this paper proposes a node-state-aware(NSA)routing algorithm.The algorithm uses the ratio of the circuit node's transmission rate to the bandwidth to represent the node's transmission capacity,and avoids using malicious nodes with low transmission capacity.Moreover,the algorithm records the frequency of node selection over a period of time,and by reducing the selection frequency of high-frequency node,the anonymous information entropy of the system is increased.Experiments on the simulation platform prove that the NSA algorithm can effectively resist hostile attacks by malicious nodes that falsely report bandwidth,and has higher anonymity security and better load balancing performance.Based on the improved routing algorithm above,we developed an instant messaging(IM)system for the Android platform.The system includes an Android client and a background server.The paper introduces the system's requirements analysis,summary design,and functional module design;it describes the construction of Tor bridge,the implementation of NSA algorithm,and the detailed design and implementation of the server and client of the system;finally,the instant messaging system is tested in terms of functionality,performance,anonymity,and circuit comparison.The test results show that the improved routing algorithm can bring stronger anonymous features and load balancing capability to the instant messaging system.