A Brief Introduction to Certificateless Encryption Schemes and Their Infrastructures

Certificateless encryption is a form of public-key encryption that is designed to eliminate the disadvantages of both traditional PKIbased public-key encryption scheme and identity-based encryption. Unlike public-key encryption, there is no requirement for digital certificates or a public-key infrastructure. Unlike identity-based encryption, the trusted third party need not be given the ability to decrypt ciphertexts intended for users. In this invited paper we will review the concept of certificateless encryption from an infrastructure point of view and show that many of the different formulations for “certificateless” encryption can be instantiated using public-key infrastructures after all.