Protecting router cache privacy in named data networking

With users´ explosively increasing needs for online data, current IP-based or host-based Internet architecture is becoming insufficient and outdated gradually. Named Data Networking (NDN) is considered as a candidate of next-generation Internet architectures. In NDN, an addressable content name, rather than an IP address, is used to publish, request, deliver and manage the content. In addition, NDN employs router caches to replicate and store passing packets, so that previously requested contents can be delivered very quickly. Although router caching can improve network throughput significantly, it also introduces a few serious privacy problems. In this paper, we focus on studying snooping attack, in which a snooper can learn about other users´ preferences and breach their privacy by measuring the time difference between responses. To address this problem, we utilize the signatures of abnormal events to detect abnormal user behaviors, and build a credit score for each user according to his behaviors. When the credit score of a user drops below a predefined threshold, this user is considered as a snooper. Then, we deliberately add a response delay to the snooper so that he can be isolated from normal users. The performance analysis shows that our scheme can efficiently protect router caching privacy against snooping attack, with keeping high network performance.