Pricing via Processing or Combatting Junk Mail

  • Cynthia Dwork
  • Moni Naor
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 740)


We present a computational technique for combatting junk mail in particular and controlling access to a shared resource in general. The main idea is to require a user to compute a moderately hard, but not intractable, function in order to gain access to the resource, thus preventing frivolous use. To this end we suggest several pricing functions, based on, respectively, extracting square roots modulo a prime, the Fiat-Shamir signature scheme, and the Ong-Schnorr-Shamir (cracked) signature scheme.


Hash Function Signature Scheme Difference Parameter Price Function Hard Function 
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 1993

Authors and Affiliations

  • Cynthia Dwork
    • 1
  • Moni Naor
    • 1
  1. 1.IBM Almaden Research CenterSan Jose

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