关键词: RSA公钥系统, 双向匿名秘密通信, 网络安全, 洋葱路由

Abstract: In the network,the identity of communicators is an important privacy.Anonymous communications can hide the sender and the recipient.Most of the research on anonymous communication is about the sender’s anonymity.There is less research on the receiver’s anonymity and bidirectional anonymity.In onion routing system,onion path is constructed by using source routing protocol and layer by layer encryption.The message is forwarded through orderly transit nodes according to onion path,which hides the sender’s address,realizes the sender’s anonymity and effectively prevents eavesdropping and traffic analysis.A new bidirectional anonymous secret communication protocol was proposed based on onion routing in this paper.The onion path constructed by the sender contains all the nodes in the system.Every hopping transfer node must judge whether the node is the receiver or not.If not,the message continues to be forwarded,and else,the recipient receives the message and the forwarding terminates.The identity of the sender(receiver) is not captured by the other party or any other user.Besides both sides of the communication,any transit node or intrudercan’t get the message.Therefore,the protocol achieves a two-way anonymous secret communication well.The anonymity of the receiver is realized without multicast,which effectively reduces the traffic in the system.The protocol is only based on onion routing anonymity system and is relatively simple.The experimental results show that with the increase of system users,the average response time and the average bidirectional communication time increase almost linearly,which indicates that the system is still stable and robust in the case of a large number of users.

Key words: Bidirectional anonymity secret communication, Network security, Onion routing, RSA public key system