Off-Line Karma: A Decentralized Currency for Peer-to-peer and Grid Applications

  • Flavio D. Garcia
  • Jaap-Henk Hoepman
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3531)


Peer-to-peer (P2P) and grid systems allow their users to exchange information and share resources, with little centralised or hierarchical control, instead relying on the fairness of the users to make roughly as much resources available as they use. To enforce this balance, some kind of currency or barter (called karma) is needed that must be exchanged for resources thus limiting abuse. We present a completely decentralised, off-line karma implementation for P2P and grid systems, that detects double-spending and other types of fraud under varying adversarial scenarios. The system is based on tracing the spending pattern of coins, and distributing the normally central role of a bank over a predetermined, but random, selection of nodes. The system is designed to allow nodes to join and leave the system at arbitrary times.


Decentralised systems micropayments free-riding security grid peer-to-peer 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Flavio D. Garcia
    • 1
  • Jaap-Henk Hoepman
    • 1
  1. 1.Institute for Computing and Information ScienceRadboud UniversityNijmegenThe Netherlands

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