Abstract: The national production of Industry Control System (ICS) is imperative, and a more secure and reliable identification method is urgently needed. PLC-centric system is a typical ICS, and the Public Key Infrastructure (PKI) can solve the authenticity of the identity of both communication parties. This paper studies PKI based on the national secret algorithm in a PLC-centric ICS, and gives the certificate authentication model of ICS and the deployment design of PKI. Then taking the open source framework OpenSSL for example, using the engine technology, the paper analyzes the combination of the national secret algorithm and PKI, and gives the pivotal structures and algorithm design of the SM2, SM3 extended to OpenSSL. Finally, the paper designs a PKI management system for ICS, then develops and implements the system. All the work of this paper provides a good basis for the application of PKI to the ICS, and provides a new idea for the security of the identity authentication of the ICS.

Key words: ICS, PKI, nation secret algorithm, OpenSSL, engine, identification