Abstract:

In order to deal with the cache pollution attacks in Content Centric Networking (CCN), a defense scheme based on cache diversification was proposed. To reduce the attack scope, the in-network content services were divided into three categories and different cache strategies were used for different services. For private and real-time services, contents were directly delivered without being cached; for streaming media services, contents were pushed to be cached in the edge of network according to probablity; for document services, the priority was caching contents in the upstream, then pushing them to the downstream. Then different defense methods were configured on different nodes. For the edge nodes, attacks were detected by observing the request probability variation of different contents; for the upstream nodes, contents with low request rate were ruled out from the cache space by setting filter rules. The simulation results show that the network average hit ratio under service diversification mechanism is 17.3% higher than that under CCN with traditional caching strategies.The proposed scheme can effectively improve the defense capability of the network for the cache pollution attack.

Key words: Content Centric Networking (CCN), cache pollution attack, cache strategy, service diversification, defense mechanism

摘要：

针对内容中心网络(CCN)中的缓存污染攻击问题,提出一种基于多样化存储的缓存污染防御机制。对不同业务内容采取差异化缓存从而减小网络受攻击面,将业务划分为三类并采用不同缓存策略:对隐私及实时性业务不予缓存;对流媒体业务以概率推送至网络边缘缓存;对其他文件类内容业务由上游到边缘逐步推送缓存。在不同节点分别配置不同的缓存污染攻击防御手段:对于边缘节点通过内容请求到达概率的变化对攻击进行检测;对于上游节点通过设置过滤规则将请求概率较低的内容排除出缓存空间。仿真结果表明,相比CNN传统缓存策略下的防御效果,该机制使网络平均缓存命中率提高了17.3%,该机制能够有效提升网络对于缓存污染攻击的防御能力。

关键词: 内容中心网络, 缓存污染攻击, 缓存策略, 业务多样化, 防御机制