Pollution attacks and defenses for Internet caching systems

Leiwen Deng*, Yan Gao, Yan Chen, Aleksandar Kuzmanovic

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


Proxy caching servers are widely deployed in today's Internet. While cooperation among proxy caches can significantly improve a network's resilience to denial-of-service (DoS) attacks, lack of cooperation can transform such servers into viable DoS targets. In this paper, we investigate a class of pollution attacks that aim to degrade a proxy's caching capabilities, either by ruining the cache file locality, or by inducing false file locality. Using simulations, we propose and evaluate the effects of pollution attacks both in Web and peer-to-peer (p2p) scenarios, and reveal dramatic variability in resilience to pollution among several cache replacement policies. We develop efficient methods to detect both false-locality and locality-disruption attacks, as well as a combination of the two. To achieve high scalability for a large number of clients/requests without sacrificing the detection accuracy, we leverage streaming computation techniques, i.e., bloom filters and probabilistic counting. Evaluation results from large-scale simulations show that these mechanisms are effective and efficient in detecting and mitigating such attacks. Furthermore, a Squid-based implementation demonstrates that our protection mechanism forces the attacker to launch extremely large distributed attacks in order to succeed.

Original languageEnglish (US)
Pages (from-to)935-956
Number of pages22
JournalComputer Networks
Issue number5
StatePublished - Apr 10 2008


  • False-locality
  • Locality-disruption
  • Proxy-cache-targeted

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Electrical and Electronic Engineering


Dive into the research topics of 'Pollution attacks and defenses for Internet caching systems'. Together they form a unique fingerprint.

Cite this