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On weak RSA-keys produced from pretty good privacy

  • Session 10: Cryptanalysis of Public Key Systems
  • Conference paper
  • First Online:
Information and Communications Security (ICICS 1997)

Part of the book series: Lecture Notes in Computer Science ((LNCS,volume 1334))

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  • 241 Accesses

Abstract

We report that Pretty Good Privacy (PGP) generates weak RSA-moduli which is vulnerable against P + l-factoring attack, because PGP's algorithm for generating prime numbers is designed only to produce a large prime number P so that P - 1 has a large prime factor. We count the number of weak keys in PGP via experimental computation with theoretical consideration. Our obtained results show that bad primes are generated in PGP and induced weak keys can be easily breakable via P + 1-factoring method. For example, in the case of RSA-key with 512-bit, we could attack

  1. 1.

    0.3% users' systems with only 15 hours single PC-computation (very weak keys!!),

  2. 2.

    2% users' systems with 50 days single PC-computation (weak keys!).

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Author information

Authors and Affiliations

  1. Mitsubishi Electric Corporation, 5-1-1 Ofuna, Kamakura, 247, Kanagawa, Japan

    Yasuyuki Sakai & Hirokazu Ishizukal

  2. Kyushu University, 6-10-1 Hakozaki, Higashi-ku, 812-81, Fukuoka, Japan

    Kouichi Sakurai

Authors
  1. Yasuyuki Sakai
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  2. Kouichi Sakurai
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  3. Hirokazu Ishizukal
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Editor information

Yongfei Han Tatsuaki Okamoto Sihan Qing

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© 1997 Springer-Verlag

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Sakai, Y., Sakurai, K., Ishizukal, H. (1997). On weak RSA-keys produced from pretty good privacy. In: Han, Y., Okamoto, T., Qing, S. (eds) Information and Communications Security. ICICS 1997. Lecture Notes in Computer Science, vol 1334. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0028487

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  • DOI: https://doi.org/10.1007/BFb0028487

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  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-63696-0

  • Online ISBN: 978-3-540-69628-5

  • eBook Packages: Springer Book Archive

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