Pong-Cache Poisoning in GUESS (Extended Technical Report)

Abstract

This paper studies the problem of resource discovery in unstructured peer-to-peer (P2P) systems. We propose simple policies that make the discovery of resources resilient to coordinated attacks by malicious nodes. We focus on a novel P2P protocol called GUESS that uses a pong cache, a set of currently known nodes, to discover new ones. We describe how to limit pong cache poisoning, a condition in which the ids of malicious nodes appear in the pong caches of good nodes. We propose adding an introduction protocol (IP) as a basic mechanism to GUESS to ensure liveness. We suggest using a most-recently-used (MRU) cache replacement policy to slow down the rate of poisoning, and an ID smearing algorithm (IDSA) to limit poisoning in the steady-state. We also determine the marginal utility of using a malicious node detector (MND) to further limit poisoning, and the level of accuracy required of the detector.