Biblio

Supervisory Control and Data Acquisition (SCADA) systems are utilized extensively in critical power grid infrastructures. Modern SCADA systems have been proven to be susceptible to cyber-security attacks and require improved security primitives in order to prevent unwanted influence from an adversarial party. One section of weakness in the SCADA system is the integrity of field level sensors providing essential data for control decisions at a master station. In this paper we propose a lightweight hardware scheme providing inferred authentication for SCADA sensors by combining an analog to digital converter and a permutation generator as a single integrated circuit. Through this method we encode critical sensor data at the time of sensing, so that unencoded data is never stored in memory, increasing the difficulty of software attacks. We show through experimentation how our design stops both software and hardware false data injection attacks occurring at the field level of SCADA systems.

Embedded systems in physically insecure environments are subject to additional security risk via capture by an adversary. A captured microchip device can be reverse engineered to recover internal buffer data that would otherwise be inaccessible through standard IO mechanisms. We consider an adversary who has sufficient ability to gain all internal bits and logic from a device at the time of capture as an unsolved threat. In this paper we present a novel sensing architecture that enhances embedded system security by randomly encoding sensed values. We randomly encode data at the time of sensing to minimize the amount of plaintext data present on a device in buffer memory. We encode using techniques that are unintelligible to an adversary even with full internal bit knowledge. The encoding is decipherable by a trusted home server, and we have provided an architecture to perform this decoding. Our experimental results show the proposed architecture meets timing requirements needed to perform communications with a satellite utilizing short-burst data, such as in remote sensing telemetry and tracking applications.