The Study Of Software Architecture Of Anonymous System Tor And Traffic Camouflaging

With the rapid development of the internet,the characteristics of information diversification and transparency are becoming more and more obvious.People also paid more and more attention to the protection of their own privacy information.Anonymous system through hierarchical encryption,traffic confusion and other ways can effectively protect user privacy,which is currently the most widely used tor network,that is,the second generation of onion routing.As of March 2019,more than 1 million of users were using the onion network.The tor network confuses real traffic in the network,destroys traffic characteristics,and protects user privacy by sending camouflage traffic during link inactivity.However,at present,there is a single way of dummy traffic delivery and generation in the traffic camouflage scheme in tor network.Therefore,by combining several mainstream traffic camouflage technologies and the traffic camouflage implementation scheme of the anonymous system tor in the current version,we design and implement a discrete traffic camouflage system.In this paper we firstly introduce the background of tor network and its user growth process,as well as the principle of traffic camouflage scheme in the current version of tor network.Then we expound the background of traffic camouflage technology,and summarize several more mainstream traffic camouflage technologies in the current academic,including fixed-rate padding,dependent link padding and adaptive padding.Secondly,this paper systematically analyzes the software architecture and implementation principle of the anonymous system tor.This paper also introduces the operation principle,module division and version iteration of tor respectively.Then we focus on several core processes of tor,including the system bootstrap process,the second callback process,and the link building process.And we analyze the scheme of traffic padding in tor and summarize the shortcomings of this scheme.Finally,this paper proposes a pseudo-traffic transmission mechanism such as drop-in,half-way discarding and so on.Based on this mechanism,we design a discretized traffic camouflage system.And expounds the system from the aspects of system architecture,module division,core process and so on.In the system,calculating the persistent user data to obtain the data packet byte,the sending time and the IP address required for constructing pseudo-traffic packet,and calculating the bandwidth consumption of current circuit to select adaptive transmission mechanism,then it transfers the pseudo-traffic to tor network.By analyzing the system test,it is verified that each module of the system can run normally,and generate and send dummy traffic normally.