Time synchronization security deployment plan for industrial control systems in the guidance of timing security protection

　　With the continuous improvement of intelligent networking of industrial control systems, various control devices, monitoring terminals, and automation systems in production sites are fully connected to the network, and precise time synchronization has become the foundation for stable operation of industrial production. At the same time, security risks such as network attacks, illegal timing tampering, and synchronous message hijacking have increased. Once the industrial system time benchmark is maliciously tampered with, it can easily cause production process disruptions, equipment linkage abnormalities, data log failures, and directly affect the stability of factory production. Zhejiang Saisi Electronic Technology Co., Ltd. has compiled safety protection ideas for industrial control system timing based on actual industrial application scenarios, shared standardized time synchronization safety deployment plans, and helped enterprises build a solid defense line for industrial network timing security.

　　The main safety risks faced by industrial control system timing

　　In an open networking environment, there are multiple security risks in the industrial time synchronization system. Firstly, there is the risk of illegal time source access, as external unknown time signals invade the internal network and replace the original standard time reference, causing chaos in the timing of equipment throughout the factory and disrupting the pace of automated production. Secondly, there is the risk of synchronous message tampering and hijacking. Unscrupulous personnel tamper with the timing interaction data through network means, modify the local time of the device, resulting in timing errors in the issuance of operation instructions, causing mechanical action misalignment, assembly line shutdown and other faults.

　　In addition, the timing architecture without permission isolation is prone to problems such as arbitrary access of terminals to the synchronization network and arbitrary modification of backend parameters. This not only affects the stability of time synchronization, but also brings potential intrusion points to the entire industrial control network, which is not conducive to the overall network security control of the factory area.

　　Basic principles for timing and security deployment of industrial control systems

　　To build a safe and reliable industrial time synchronization system, the first step is to follow the principle of scientific deployment. Firstly, adhere to the principle of independent timing within the internal network, divide dedicated timing network areas, physically or logically isolate industrial timing equipment from the office external network, and block the penetration channels of external insecure networks. The second principle is to adhere to the principle of hierarchical control of permissions, setting hierarchical settings for login permissions, parameter modification permissions, and terminal access permissions for time synchronization devices, clarifying the scope of operation for different operation and maintenance personnel, and preventing unrelated personnel from arbitrarily changing synchronization configurations. The third principle is to adhere to the principle of redundant and secure backup, establish a multi-path time synchronization architecture, set up backup synchronization links and local timing mechanisms, automatically switch stable time benchmarks when the main timing link is abnormal or encounters interference, and ensure uninterrupted production timing throughout the entire process.

　　Practical deployment plan for time synchronization security in industrial control systems

　　1. Build an isolated exclusive timing network

　　In the industrial plant network planning, a dedicated time synchronization network segment is separately divided, and the core timing equipment is deployed in a secure intranet area, prohibiting direct external mapping access. All industrial control terminals PLC、 Intelligent instruments and monitoring hosts obtain standard time uniformly from the internal network, without directly referencing public time sources from the external network, reducing the risk of external attacks from the network architecture level.

　　2. Enable secure timing protocol and encryption mechanism

　　In terms of protocol selection, priority should be given to synchronous transmission methods with security protection capabilities, enabling protection functions such as message verification and identity authentication, verifying and identifying interactive synchronous data, automatically filtering abnormal data packets and false timing instructions, intercepting illegal synchronization requests, and avoiding malicious data intrusion into industrial control systems.

　　3. Implement strict access management for terminal access

　　Standardize the timing access standards for all industrial equipment within the factory area, set up a whitelist for access, and only allow devices registered within the factory area to access the time synchronization system. For newly added devices, timing permissions can only be granted after completing security verification and information registration, controlling the number of access terminals from the source and reducing security risks caused by unknown devices.

　　4. Improve equipment operation monitoring and abnormal alarm

　　Monitor the operation status of the entire time synchronization system 24/7, and view real-time synchronization status, time deviation, number of access terminals, and data exchange situation. Once there is a significant time offset, unfamiliar device access, or abnormal synchronization message, the system will automatically trigger an alarm reminder, making it convenient for operation and maintenance personnel to investigate and dispose of security risks in a timely manner.

　　5. Regularly conduct safety inspections and optimize strategies

　　Establish a normalized timing security inspection mechanism, regularly check device login logs, parameter modification records, and synchronous operation logs, and promptly fix configuration vulnerabilities. Combining the adjustment of the factory production structure with new network security regulations, continuously optimizing the timing protection strategy, updating access control rules, and adapting to the constantly changing industrial security protection needs.

　　Saisi Industrial Time Safety Supporting Services

　　Zhejiang Saisi Electronics focuses on creating a comprehensive solution for time synchronization in the industrial field. It can customize a time synchronization deployment plan that combines stability and security according to the industrial control layout, production scale, and safety level requirements of different factory areas. The relevant timing supporting equipment is adapted to the harsh industrial usage environment, comes with multiple security protection configurations, and conforms to security regulations such as industrial intranet isolation deployment and hierarchical permission management.

　　At the same time, it can provide one-stop services for enterprises, such as pre network planning, on-site deployment guidance, and post security operation and maintenance suggestions, to help enterprises quickly complete the construction of a compliant, secure, and stable industrial time synchronization system. On the premise of ensuring accurate timing, it comprehensively safeguards the smooth and efficient operation of industrial control systems.