An IND-CCA2 public-key cryptosystem with fast decryption

Johannes Buchmann, Kouichi Sakurai, Tsuyoshi Takagi

研究成果: 書籍/レポート タイプへの寄稿会議への寄与

5 被引用数 (Scopus)


We propose an IND-CCA2 public-key cryptosystem with fast decryption, called the NICE-X cryptosystem. Its decryption time is the polynomial time of degree 2 by the bit-length of a public-key D, i.e., O((log |D|)2), and the cost of two hash functions. The NICE-X is an enhancement of the NICE cryptosystem, which is constructed over the quadratic class group Cl(D). We first show that the one-wayness of the encryption of the NICE cryptosystem is as intractable as the Smallest Kernel Equivalent Problem (SKEP). We also prove that the NICE cryptosystem is IND-CPA under the Decisional Kernel Problem (DKP). Then we prove that the NICE-X cryptosystem is IND-CCA2 under the SKEP in the random oracle model. Indeed, the overhead of the decryption of the NICE-X from the NICE is only the cost of one ideal multiplication and two hash functions. Our conversion technique from the NICE to the NICE-X is based on the REACT. However we modify it to be suitable for the NICE. A message of the NICE-X is encrypted with the random mask of the encryption function of the NICE, instead of the encrypted key. Then the reduced security problem of the NICE-X is enhanced from the Gap-SKEP to the SKEP.

ホスト出版物のタイトルInformation Security and Cryptology - ICISC 2001 - 4th International Conference, Proceedings
編集者Kwangjo Kim
出版社Springer Verlag
ISBN(印刷版)3540433198, 9783540433194
出版ステータス出版済み - 2002
イベント4th International Conference on Information Security and Cryptology, ICISC 2001 - Seoul, 韓国
継続期間: 12月 6 200112月 7 2001


名前Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)


その他4th International Conference on Information Security and Cryptology, ICISC 2001

!!!All Science Journal Classification (ASJC) codes

  • 理論的コンピュータサイエンス
  • コンピュータサイエンス一般


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