Proofs of Communication and Its Application for Fighting Spam

  • Marek Klonowski
  • Tomasz Strumiński
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4910)


In this paper we present a communicational proof-of-work – a new tool that can be used, among others, for filtering messages and limiting spam. Our idea can be regarded as an analogue of regular proofs-of-work introduced by Dwork and Naor. The idea presented in our paper is as follows: the prover has to provide a convincing evidence that he had communicated with other, randomly chosen entity. This approach is essentially different from previous proofs-of-work, because fulfilling this requirement does not depend on resources owned by the prover (e.g. sender) only. Thanks to this, even if the adversary (e.g. spammer) has an access to much more efficient computers, he does not have any important advantage over regular, honest users of the system. We also demonstrate some other applications of the presented idea as well as some extensions based on its combination with regular proofs-of-work. Together with algorithms we also briefly describe a proof of our concept i.e. working implementation. We present some experimental data and statistics obtained during tests of our application.


Hash Function Signature Scheme Dynamic Content Honest User Dynamic Page 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Marek Klonowski
    • 1
  • Tomasz Strumiński
    • 1
  1. 1.Institute of Mathematics and Computer ScienceWrocław University of TechnologyPoland

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