Research On Censorship Circumvention Anonymous Techniques

Since the birth of the Internet,People's lives are deeply changed with the rapid popularization and fast development of all kinds of network techniques.With the Internet,communication and information transportation become more effective than it ever was.However,contrast to the very beginning purpose of Internet that making people freely access and publish information,network censorship exists almost everywhere in the network world.As a significant application of anonymous communication,anonymous censorship circumvention techniques have attracted much attention and academic efforts during the past decades.Research on anonymous censorship circumvention techniques has become a popular subject in the field of computer network and network security.Firstly,this thesis provides an investigation on anonymous communication and network censorship techniques.A review of associate anonymous techniques is given in this part.And network censorship techniques are studied and categorized.Secondly,this thesis comprehensively studied the anonymous censorship circumvention techniques,including current study status of anonymous censorship circumvention technique,anonymous censorship circumvention systems based on network proxy,anonymous censorship circumvention systems based on integrating network infrastructure and anonymous censorship circumvention systems based on network traffic obfuscation and network traffic morphing.Lastly,this thesis analyzed the current anonymous censorship circumvention systems based on HTTP traffic morphing on their deniability,performance,anonymity and so on.Then a new anonymous censorship circumvention system based on picture traffic simulation PSTA.Then,the overall architecture,upward traffic and downward traffic design,and the critical components are analyzed and discussed.The implementation and analysis are given at the last of this thesis.