Modified ElGamal cryptosystem

  • Daisuke Nakamura
  • Kunikatsu Kobayashi
Public-Key Cryptography
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1396)


We propose a modified ElCamal cryptosystem which can broadcast communicate by encrypting every different plaintext (same plaintext is also acceptable) for plural users, and is also applicable to the systems which have hierarchical structures. And, we show that the security of this cryptosystem is based on difficulties of solving discrete logarithm problems , it maintains equivalent security with the original ElGamal cryptosystem. The transmission efficiency of this cryptosystem is improved.


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    N.Ikeno and K.Koyama, “Modern cryptography,” The Institute of Electronics, Information and Communication Engineers, 1986.Google Scholar
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    E.Okamoto, “Introduction to cryptography,” Kyoritsu Syuppan, 1993.Google Scholar
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    Y.Zheng and T.Matsumoto, “Breaking real-world implementations of cryptosystems by manipulating their random number generation,” SCIS'97-6B, 1997.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Daisuke Nakamura
    • 1
  • Kunikatsu Kobayashi
    • 1
  1. 1.Department of Electrical and Information Engineering, Faculty of EngineeringYamagata UniversityYonezawaJapan

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