Pairing-Based Cryptography – Pairing 2007

Volume 4575 of the series Lecture Notes in Computer Science pp 83-107

General and Efficient Certificateless Public Key Encryption Constructions

  • Zhaohui ChengAffiliated withSchool of Computing Science, Middlesex University, London
  • , Liqun ChenAffiliated withHewlett-Packard Laboratories, Bristol
  • , Li LingAffiliated withDepartment of Communication Science and Engineering, Fudan University, Shanghai
  • , Richard ComleyAffiliated withSchool of Computing Science, Middlesex University, London

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In 2003, Al-Riyami and Paterson introduced a new public key encryption paradigm called Certificateless Public Key Encryption (CL-PKE), which like Identity-Based Encryption (IBE) is certificatefree, and meanwhile which unlike IBE but similar to certificate-based encryption is key-escrow-free. In this paper, based on a heuristic observation on some existing IBE schemes and PKE schemes, we propose a general approach to build a CL-PKE solution, which makes use of a simple combination of an IBE scheme, a Diffie-Hellman type key establishment algorithm and a secure hash-function. Following this approach we construct two efficient concrete CL-PKE schemes and formally analyse their security in the random oracle model.