Computational puzzles as sybil defenses

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

Abstract

We consider the problem of defending against Sybil attacks using computational puzzles. A fundamental difficulty in such defenses is enforcing that puzzle solutions not be reused by attackers over time. We propose a fully decentralized scheme to enforce this by continually distributing locally generated challenges that are then incorporated into the puzzle solutions. Our approach consists of an all-to-all broadcast of challenges, with a combining function to ensure this can be done efficiently. The combining function generates certificates that can be used to prove that each node's challenge was delivered to and used by each other node, therefore proving the freshness of each puzzle. We show how our distribution and verification mechanisms can be implemented on top of the the Chord [21] overlay.

Original languageEnglish (US)
Title of host publicationProceedings - 6th IEEE International Conference on Peer-to-Peer Computing, P2P 2006
EditorsAlberto Montresor, Adam Wierzbicki, Nahid Shahmehri
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages171-176
Number of pages6
ISBN (Electronic)0769526799, 9780769526799
DOIs
StatePublished - 2006
Event6th IEEE International Conference on Peer-to-Peer Computing, P2P 2006 - Cambridge, United Kingdom
Duration: Sep 6 2006Sep 8 2006

Publication series

NameProceedings - 6th IEEE International Conference on Peer-to-Peer Computing, P2P 2006

Conference

Conference6th IEEE International Conference on Peer-to-Peer Computing, P2P 2006
CountryUnited Kingdom
CityCambridge
Period9/6/069/8/06

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Hardware and Architecture
  • Safety, Risk, Reliability and Quality

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