BrieflyIn the previous article, I clearly described the structure of the S7CommPlus protocol and debugged OMSp_core_managed.dll to understand the cryptographic authentication and communication handshake process. From there, we find the position of the functions to calculate the main parameters such as Symmetric key checksum, public key checksum…

IntroductionSiemens PLC is often used in ISC industrial control systems to perform important logic actions of the operation process. New versions of Siemens PLC from s7-1500 and s7-1200V4.0 used an encryption protocol s7CommPLus to protect against replay attacks. The study below, it can be applied in the SCADA-Based OT