Public Key Identification Based on the Equivalence of Quadratic Forms

  • Rupert J. Hartung
  • Claus-Peter Schnorr
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4708)


The computational equivalence problem for quadratic forms is shown to be NP-hard under randomized reductions, in particular for indefinite, ternary quadratic forms with integer coefficients. This result is conditional on a variant of the Cohen-Lenstra heuristics on class numbers. Our identification scheme proves knowledge of an equivalence transform.


Quadratic Form Class Group Class Number Arithmetic Progression Chinese Remainder Theorem 
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 2007

Authors and Affiliations

  • Rupert J. Hartung
    • 1
  • Claus-Peter Schnorr
    • 1
  1. 1.Johann Wolfgang Goethe Universität Frankfurt a. M., Postfach 11 19 32; Fach 238, 60054 Frankfurt a. M.Germany

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