HIGH SECURITY WITH LOW LATENCY IN LEGACY SCADA SYSTEMS

摘要

Message authentication with low latency is necessary to ensure secure operations in legacy industrial control networks such as those in the power grid. Previous authentication solutions that examine single messages incur noticeable latency. This paper describes Predictive YASIR, a bump-in-the-wire device that reduces the latency by considering broader patterns of messages. The device predicts the incoming plaintext based on previous observations; compresses, encrypts and authenticates data online; and pre-sends a portion of the ciphertext before receiving the entire plaintext. The performance of Predictive YASIR is evaluated using a simulation involving the Modbus/ASCII protocol. By considering broader message patterns and using predictive analysis, improvements in latency of 15.48 ± 0.35% are obtained.