Timing Attacks on Access Privacy in Information Centric Networks and Countermeasures

In recently proposed information centric networks (ICN), a user issues “interest” packets to retrieve contents from network by names. Once fetched from origin servers, “data” packets are replicated and cached in all routers along routing and forwarding paths, thus allowing further interests from other users to be fulfilled quickly. However, the way ICN caching and interest fulfillment work poses a great privacy risk: the time difference between responses for an interest of cached and uncached content can be used as an indicator to infer whether or not a near-by user has previously requested the same content as that requested by an adversary. This work introduces the extent to which the problem is applicable in ICN and provides several solutions that try to strike a balance between cost and benefits, and raise the bar for an adversary to apply such attack.