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A Note on An Encryption Scheme of Kurosawa and Desmedt

Authors:
Rosario Gennaro
Victor Shoup
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URL: http://eprint.iacr.org/2004/194
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Abstract: Recently Kurosawa and Desmedt presented a new hybrid encryption scheme which is secure against adaptive chosen-ciphertext attack. Their scheme is a modification of the Cramer-Shoup encryption scheme. Its major advantage with respect to Cramer-Shoup is that it saves the computation of one exponentiation and produces shorter ciphertexts. However, the proof presented by Kurosawa and Desmedt relies on the use of information-theoretic key derivation and message authentication functions. In this note we present a different proof of security which shows that the Kurosawa-Desmedt scheme can be instantiated with any computationally secure key derivation and message authentication functions, thus extending the applicability of their paradigm, and improving its efficiency.
BibTeX
@misc{eprint-2004-12166,
  title={A Note on An Encryption Scheme of Kurosawa and Desmedt},
  booktitle={IACR Eprint archive},
  keywords={public-key cryptography / public-key encryption, chosen ciphertext security},
  url={http://eprint.iacr.org/2004/194},
  note={ shoup@cs.nyu.edu 12921 received 10 Aug 2004, last revised 18 May 2005},
  author={Rosario Gennaro and Victor Shoup},
  year=2004
}