International Workshop on Public Key Cryptography

PKC 2006: Public Key Cryptography - PKC 2006 pp 474-490

On Constructing Certificateless Cryptosystems from Identity Based Encryption

  • Benoît Libert
  • Jean-Jacques Quisquater
Conference paper

DOI: 10.1007/11745853_31

Volume 3958 of the book series Lecture Notes in Computer Science (LNCS)
Cite this paper as:
Libert B., Quisquater JJ. (2006) On Constructing Certificateless Cryptosystems from Identity Based Encryption. In: Yung M., Dodis Y., Kiayias A., Malkin T. (eds) Public Key Cryptography - PKC 2006. PKC 2006. Lecture Notes in Computer Science, vol 3958. Springer, Berlin, Heidelberg


Certificateless cryptography (CL-PKC) is a concept that aims at enjoying the advantages of identity based cryptography without suffering from its inherent key escrow. Several methods were recently suggested to generically construct a certificateless encryption (CLE) scheme by combining identity based schemes with ordinary public key cryptosystems. Whilst the security of one of these generic compositions was proved in a relaxed security model, we show that all them are insecure against chosen-ciphertext attacks in the strongest model of Al-Riyami and Paterson. We show how to easily fix these problems and give a method to achieve generic CLE constructions which are provably CCA-secure in the random oracle model. We finally propose a new efficient pairing-based scheme that performs better than previous proposals without pre-computation. We also prove its security in the random oracle model.


Certificateless encryptionprovable securitybilinear maps
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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Benoît Libert
    • 1
  • Jean-Jacques Quisquater
    • 1
  1. 1.Microelectronics Laboratory, Crypto GroupUCLLouvain-La-NeuveBelgium