网络层匿名通信协议综述

匿名通信系统是一种建立在应用层之上结合利用数据转发、内容加密、流量混淆等多种隐私保护技术来隐藏通信实体关系和内容的覆盖网络。然而，作为覆盖网络运行的匿名通信系统，在性能和安全保障上的平衡问题上存在不足。未来互联网架构的出现使构建基于基础设施的匿名通信系统成为可能。此类匿名通信系统将匿名设计为网络基础设施服务，通过为路由器配备加密操作，可解决匿名网络的可拓展性和性能限制的部分问题，因此也可称它们为网络层匿名通信协议。对现有的网络层匿名通信协议（LAP、Dovetail、Hornet、PHI和Taranet）进行了研究，介绍了网络层匿名通信协议的分类标准，简述其创新点和具体加密思想，并对它们如何在安全性和性能二者之间的权衡进行分析，也指出了这几种网络匿名通信协议的优势和不足，最后提出在匿名通信系统发展的过程中所面临的挑战和需要深入研究的问题。

Survey of network-layer anonymous communication protocols

An anonymous communication system is an overlay network built on the application layer and combining various privacy protection technologies such as data forwarding,content encryption,and traffic obfuscation to hide communication relationships between entities and forwarded contents.However,there is a deficiency in the balance between performance and security as an anonymous communication system operating over an overlay network.With the advance of the future internet architectures,it is possible to build an infrastructure-based anonymous communication system.Such anonymous communication systems design anonymity as network infrastructure services and provide encryption operations for routers,which can solve the part problem of scalability and performance limitations of anonymous network.They can also be called network-layer anonymous communication protocols.The existing network-layer anonymous communication protocols(LAP,Dovetail,Hornet,PHI and Taranet)were studied.The classification standard of network-layer anonymous communication protocols were introduced.Its innovation point and specific encryption ideas were briefly described,and how to keep balance between security and performance was analyzed.The shortcomings and advantages of these kinds of network anonymous communication protocols were also pointed out.Finally,the challenges faced in the development of anonymous communication systems and the problems that need to be studied in depth were proposed.