Abstract: Certificateless public key cryptosystem has appealing features,namely it does not require the use of certificates and does not have a private key escrow problem,and it can to some extent solve the problem of time consuming and resource consuming of traditional public key cryptography.This paper proposed an elliptic curve based certificateless authentication and key agreement scheme,which includes a protocol and several core algorithms.This scheme can finish two party authentications in double communication without bilinear pairing computing,and greatly increase the efficiency of authentication by 30% compared with the formal protocols.The scheme makes the most of point addition of elliptic curve,increasing the computing speed,and it can complete the authentication and generate the shared key in 20ms without considering the network communication time consuming.The scheme also satisfies communication safety under the exposure of shared key,master key forward secrecy,perfect forward secrecy and key compromise impersonation resilience.The scheme is more suitable for the restricted computing resource of the communication environment,such as wireless sensors,Ad hoc networks,and so on.

Key words: Elliptic curve,Certificateless public key cryptosystem,Authentication,Key agreement