Breaking the collusion detection mechanism of MorphMix

Parisa Tabriz, Nikita Borisov

Research output: Chapter in Book/Report/Conference proceedingConference contribution


MorphMix is a peer-to-peer circuit-based mix network designed to provide low-latency anonymous communication. MorphMix nodes incrementally construct anonymous communication tunnels based on recommendations from other nodes in the system; this P2P approach allows it to scale to millions of users. However, by allowing unknown peers to aid in tunnel construction, MorphMix is vulnerable to colluding attackers that only offer other attacking nodes in their recommendations. To avoid building corrupt tunnels, MorphMix employs a collusion detection mechanism to identify this type of misbehavior. In this paper, we challenge the assumptions of the collusion detection mechanism and demonstrate that colluding adversaries can compromise a significant fraction of all anonymous tunnels, and in some cases, a majority of all tunnels built. Our results suggest that mechanisms based solely on a node's local knowledge of the network are not sufficient to solve the difficult problem of detecting colluding adversarial behavior in a P2P system and that more sophisticated schemes may be needed.

Original languageEnglish (US)
Title of host publicationPrivacy Enhancing Technologies - 6th International Workshop, PET 2006, Revised Selected Papers
Number of pages16
StatePublished - 2006
Event6th International Workshop on Privacy Enhancing Technologies, PET 2006 - Cambridge, United Kingdom
Duration: Jun 28 2006Jun 30 2006

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume4258 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other6th International Workshop on Privacy Enhancing Technologies, PET 2006
Country/TerritoryUnited Kingdom

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)


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