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Weak Keys in MST1

Authors:
Jens-Matthias Bohli
Maria Isabel Gonzalez Vasco
Consuelo Martínez
Rainer Steinwandt
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URL: http://eprint.iacr.org/2002/070
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Abstract: The public key cryptosystem $MST_1$ has been introduced in~\cite{MaStTr00}. Its security relies on the hardness of factoring with respect to wild logarithmic signatures. To identify `wild-like' logarithmic signatures, the criterion of being totally-non-transversal has been proposed. We give tame totally-non-transversal logarithmic signatures for the alternating and symmetric groups of degree $\ge 5$. Hence, basing a key generation procedure on the assumption that totally-non-transversal logarithmic signatures are `wild like' seems critical. We also discuss the problem of recognizing `weak' totally-non-transversal logarithmic signatures, and demonstrate that another proposed key generation procedure based on permutably transversal logarithmic signatures may produce weak keys.
BibTeX
@misc{eprint-2002-11594,
  title={Weak Keys in MST1},
  booktitle={IACR Eprint archive},
  keywords={public-key cryptography / logarithmic signatures, group based cryptography, MST1},
  url={http://eprint.iacr.org/2002/070},
  note={ mvasco@orion.ciencias.uniovi.es 11838 received 31 May 2002},
  author={Jens-Matthias Bohli and Maria Isabel Gonzalez Vasco and Consuelo Martínez and Rainer Steinwandt},
  year=2002
}