Efficient and Secure Comparison for On-Line Auctions

  • Ivan Damgård
  • Martin Geisler
  • Mikkel Krøigaard
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4586)


We propose a protocol for secure comparison of integers based on homomorphic encryption. We also propose a homomorphic encryption scheme that can be used in our protocol and makes it more efficient than previous solutions. Our protocol is well-suited for application in on-line auctions, both with respect to functionality and performance. It minimizes the amount of information bidders need to send, and for comparison of 16 bit numbers with security based on 1024 bit RSA (executed by two parties), our implementation takes 0.28 seconds including all computation and communication. Using precomputation, one can save a factor of roughly 10.


Encryption Scheme Security Parameter Homomorphic Encryption Oblivious Transfer Active Security 
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 Berlin Heidelberg 2007

Authors and Affiliations

  • Ivan Damgård
    • 1
  • Martin Geisler
    • 1
  • Mikkel Krøigaard
    • 1
  1. 1.BRICS, Dept. of Computer Science, University of Aarhus 

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