Certificateless public key cryptography

This paper introduces and makes concrete the concept of certificateless public key cryptography (CL-PKC), a model for the use of public key cryptography which avoids the inherent escrow of identity-based cryptography and yet which does not require certificates to guarantee the authenticity of public keys. The lack of certificates and the presence of an adversary who has access to a master key necessitates the careful development of a new security model. We focus on certificateless public key encryption (CL-PKE), showing that a concrete pairing-based CL-PKE scheme is secure provided that an underlying problem closely related to the Bilinear Diffie-Hellman Problem is hard.