Control system is widely used to monitor and control various industrial processes, such as oil and gas, smart grids, nuclear power plants, water treatment, telecommunication, chemicals, etc. Industrial Control Systems (ICS) require a secure communication network and real-time processing. However, most network protocols are designed only for reliable performance and are not equipped with adequate security systems. This study proposes to increase the security of data transmission but still pay attention to the speed test analysis to fulfill the real-time process. We introduce the BRC4 super encryption method with a combination of Beaufort and RC4 ciphers to improve data security, but still comply with real-time processing. The test results show that the proposed random initial key with at least 16 characters key length has a key space of (2) 128 bits. That means the proposed system is secure from brute forces attacks. The correlation and entropy analysis results for the largest data (IL-3) were 0.0001 and 7.99. Both show that cipher data’s security increases because cipher and plain data are very different and have very high randomness. The speed test results with the longest total time (encryption and decryption) and various key length combinations for IL-1, IL-2, and IL-3 data were 0.0303 seconds, 0.1555 seconds, and 0.7372 seconds, respectively. These results indicate that the proposed system still fulfills the real-time processing.