Optimistic fair exchange of digital signatures

Extended abstract
  • N. Asokan
  • Victor Shoup
  • Michael Waidner
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1403)

Abstract

We present a new protocol that allows two players to exchange digital signatures over the Internet in a fair way, so that either each player gets the other's signature, or neither player does. The obvious application is where the signatures represent items of value, for example, an electronic check or airline ticket. The protocol can also be adapted to exchange encrypted data. The protocol relies on a trusted third party, but is “optimistic,” in that the third party is only needed in cases where one player attempts to cheat or simply crashes. A key feature of our protocol is that a player can always force a timely and fair termination, without the cooperation of the other player.

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Copyright information

© Springer-Verlag 1998

Authors and Affiliations

  • N. Asokan
    • 1
  • Victor Shoup
    • 1
  • Michael Waidner
    • 1
  1. 1.IBM Zürich Research LaboratoryRüschlikonSwitzerland

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