Programmable Logic Controllers (PLCs) are a family of embedded devices that are being used to control physical processes in critical infrastructures. Similar to other embedded devices, PLCs are vulnerable to memory corruption and control-flow hijacking attacks. Because PLCs are being used for critical control applications, compromised PLCs constitute a significant security and safety risk. In this paper, we introduce a novel, PLC-compatible control-flow integrity (CFI) mechanism named ECFI to protect such devices …