Traffic Camouflaging In Anonymous Communication System

With the rapid development of Internet technology,more and more people begin to enjoy the enormous convenience provided by the Internet,which also makes it increasingly important to protect the identity security of users when communicating.As an important research direction in the field of information security,anonymous communication technology is often considered as providing anonymity to users when it comes to identity protection and online communication.Tor,the most widely used anonymous communication system,has accumulated millions of users.Tor populates cells of a fixed size and uses techniques such as layered encryption to resist traffic analysis attacks,trying to hide the user's identity-sensitive information.There are also some anonymous communication systems such as NetCamo,which insert trash packets in normal traffic.These techniques are also known as traffic camouflaging,because they change the characteristics of the original traffic so that attackers can not easily conduct traffic analysis attack.Therefore,this article will focus on the traffic camouflaging methods that commonly used in anonymous communication systems and analyze the performance of these traffic camouflaging methods.This paper first introduces the background and current research status of traffic camouflaging technology,and introduces the mainstream traffic camouflaging technologies in detail,such as independent link padding,dependent link padding,adaptive link padding,traffic morphing etc.Secondly,an improved scheme of traffic padding algorithm in fully connected network is proposed.For the existing traffic padding algorithms:direct padding algorithm and rerouting algorithm,this paper analyzes their time,space complexity and padding cost,and considers that due to the non-local influence of the rerouting algorithm,in some cases,the padding cost of the algorithm will rise sharply.In order to solve this problem,this paper proposes an improved rerouting algorithm:RO-Rerouting padding algorithm,which uses the auxiliary matrix to reduce the non-local influence and the padding cost of the original routing algorithm?This paper also compares these three algorithms and verifies the correctness and validity of RO-Rerouting algorithm.Finally,the traffic plan generation algorithm in NetCamo is studied.NetCamo is a well-known network traffic camouflaging system.In this paper,we firstly analyze the original traffic planning algorithm in NetCamo,and think that it is necessary to limit the path length of traffic transmission,and point out that the shortest path algorithm used in the original algorithm can not specify multiple traffic transmission path for a new connection.In order to solve this problem,this paper presents the k-TPG algorithm,which replaces the shortest path algorithm with K shortest paths algorithm and can generate traffic plans with multiple transmission paths for new connections.The paper then designs and realizes the k-TPG algorithm,and analyzes the k-TPG algorithm experimentally to verify the correctness and effectiveness of the algorithm.