Certificateless Identity-Concealed Authenticated Encryption Under Multi-KGC

Abstract

In the certificateless cryptography, users generate their partial private key and the Key Generation Centre (KGC) generates the other partial private key of users. In some certificateless application scenarios, a sender might want to send messages to a receiver which registers with another KGC. Unfortunately, no certificateless authenticated encryption scheme under multi-KGC has been put forward so far. In this work, we propose the first certificateless identity-concealed authenticated encryption scheme under multi-KGC. Our proposed scheme hides the public identity information of both sender and receiver from any third party. We build a security model for certificateless identity-concealed authenticated encryption scheme under multi-KGC. We prove that our proposed scheme is secure under the random oracle model. We also present a variant of our proposed scheme which supports bilateral identity-concealed authentication key exchange.