Sriharsha Etigowni, Contactless Control Flow Monitoring via Electromagnetic Emanations

Trustworthy operation of industrial control systems depends on secure and real-time code execution on the embedded programmable logic controllers (PLCs). The controllers monitor and control the critical infrastructures, such as electric power grids and healthcare platforms,and continuously report back the system status to human operators. This talk is about Zeus, a contactless embedded controller security monitor solution that will ensure its execution control flow integrity. Zeus leverages the electromagnetic emission by the PLC circuitry during the execution of the controller programs. Zeus's contactless execution tracking enables non-intrusive monitoring of security-critical controllers with tight real-time constraints. Those devices often cannot tolerate the cost and performance overhead that comes with additional traditional hardware or software monitoring modules. Furthermore, Zeus provides an air gap between the monitor (trusted computing base) and the target (potentially compromised) PLC.This eliminates the possibility of the monitor infection by the same attack vectors.Zeus monitors for control low integrity of the PLC program execution. Zeus monitors the communications between the human- machine interface and the PLC and captures the control logic binary uploads to the PLC. Zeus exercises its feasible execution paths, and fingerprints their emissions using an external electromagnetic sensor. Zeus trains a neural network for legitimate PLC execution and uses it at runtime to identify the control flow based on PLC's electromagnetic emissions. Zeus was implemented on a commercial Allen Bradley PLC, which is widely used in industry, and evaluated it on real-world control program executions. Zeus was able to distinguish between different legitimate and malicious executions with 98.9% accuracy and with zero overhead on PLC execution by design. About the speaker: Sriharsha Etigowni is a Post-Doctoral Research Associate at Purdue University.  He earned his PhD in Electrical and computer engineering from Rutgers University.  His research mainly focuses on security of cyber physical systems.  His research is to secure cyber physical systems by using physical and control in variants.  His research interests involve IoT embedded system security, trusted computing, secure boot, runtime monitoring and detection, physical side channels, and applied cryptography.Apart from academic research he also has industrial experience working for Bosch on automotive embedded systems specifically on In-vehicle communication protocols and working for Siemens on intelligent automated systems in manufacturing domain. His work spans in different areas of cyber physical systems such as power grids, drones, automotive, and critical manufacturing.