基于公共匿名网络的隐私增强通信技术研究

利用公共匿名网络实现低成本但安全性增强的隐私通信具有重要意义。为了实现这个目标，需针对节点选择、路径构建、数据传输三个环节，并在批量和非批量数据传输两种应用场景下，解决恶意节点和敏感区域规避、多径传输匿名与性能平衡、基于匿名网络的高可用性隐蔽信道设计等问题。本项目拟从匿名网络和互联网路由层综合考虑节点静态、动态特性，设计敏感节点分类体系和通用识别方法实现匿名路径安全优化；引入加权门限秘密共享机制，设计数据拆分、路径分配和数据重组方案，实现批量数据多径传输的匿名和性能折衷平衡；建立通用框架支持基于第三方和非第三方匿名网络资源的隐蔽信道数据传输，设计信号编/解码方法和基于时变前导码的信道同步机制提高非批量数据传输的隐蔽性、容错性和高效性。基于上述技术开发可实际部署的隐私增强通信工具，研究成果不仅可用于普通用户的通信隐私保护，也可作为一种低成本、易使用的隐秘通信手段应用于公安、国安、国防等部门。

It is of great significance to realize low-cost but security-enhancing private communication based on the existing public anonymous communication networks. To fulfill this goal, it’s necessary to solve the problems of how to avoid malicious nodes and sensitive regions, how to achieve a tradeoff between anonymity and performance for multipath transmission, and how to design covert channels of high usability based on anonymous communication networks, focusing on relay node selection, anonymous path construction, and secure data transmission in two application scenarios of batch and non-batch data transmission. This project intends to comprehensively consider the static and dynamic characteristics of relay nodes from both the anonymous network and the Internet routing layer, design a taxonomy of sensitive nodes and a universal identification method, and thus optimize the security of the anonymous communication path. Also, after a weighted threshold secret sharing mechanism is introduced, and the data splitting, path assignment and data recovery schemes are designed and evaluated, the project aims to achieve a balance between anonymity and transmission performance, realizing the secure transmission of batch data based on multipath transmission. Furthermore, a general framework to support data transmission via covert channels based on both third-party and non-third-party anonymous network resources is established, signal encoding/decoding algorithms and channel synchronization based on time-varying preamble codes are designed to improve the invisibility, fault tolerance and efficiency of non-batch data transmission. Finally, a deployable privacy-enhancing communication tool will be developed employing above achievements. Not only can the research results be used to protect the communication privacy of ordinary network users, but they can also be applied in departments such as public security, national security and national defense as a low-cost and convenient private communication method.