Abstract: Due to the increase of industrial control system(ICS) security accidents, cyber security in ICS has been greatly concerned in recent years. However, the research on cyber security protection still remains in the theoretical stage. A prevention measure that can be rapidly built and can reduce the key risks is urgently required. In this paper, a communication model of ICS is firstly established. Based on the model, the security risks and threats of ICS are in-vestigated, and the top urgent and critical security needs are clarified. Moreover, a corresponding security enhancing scheme is proposed with the system function and efficiency unaffected. Based on the one-way identity authentication and integrity checking of the key communication messages and combining with the timestamp checking mechanism and the registration mechanism, the proposed scheme is proved to be able to resist the camouflage, tampering, replay attacks and other common attacks, which can satisfy the system security requirements.

Key words: industrial control system, security analyses, security enhance, identity authentication, replay attack