NICE - New Ideal Coset Encryption -

  • Michael Hartmann
  • Sachar Paulus
  • Tsuyoshi Takagi
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1717)


Recently, a novel public-key cryptosystem constructed on number fields is presented. The prominent theoretical property of the public-key cryptosystem is a quadratic decryption bit complexity of the public key, which consists of only simple fast arithmetical operations. We call the cryptosystem NICE (New Ideal Coset Encryption). In this paper, we consider practical aspects of the NICE cryptosystem. Our implementation in software shows that the decryption time of NICE is comparably as fast as the encryption time of the RSA cryptosystem with e = 216+1. To show if existing smart cards can be used, we implemented the NICE cryptosystem using a smart card designed for the RSA cryptosystem. Our result shows that the decryption time of NICE is comparably as fast as the decryption time of RSA cryptosystem but not so fast as in software implementation. We discuss the reasons for this and indicate requirements for smartcard designers to achieve fast implementation on smartcards.

Key words

public-key cryptosystem fast decryption quadratic order smart card implementation 


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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Michael Hartmann
    • 1
  • Sachar Paulus
    • 2
  • Tsuyoshi Takagi
    • 3
  1. 1.Darmstadt University of TechnologyDarmstadtGermany
  2. 2.SECUDE Sicherheitstechnologie Informationssysteme GmbHDarmstadtGermany
  3. 3.NTT Information Sharing Platform LaboratoriesDüsseldorfGermany

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