Encrypted Control for Networked Systems: An Illustrative Introduction and Current Challenges

Cloud computing and distributed computing are becoming ubiquitous in many modern control areas such as smart grids, building automation, robot swarms, and intelligent transportation systems. Compared to "isolated" control systems, the main advantages of cloud-based and distributed control systems are resource pooling and outsourcing, rapid scalability, and high performance. However, these capabilities do not come without risks. In fact, the involved communication and processing of sensitive data via public networks and on third-party platforms promote (among other cyberthreats) eavesdropping and the manipulation of data (see "Summary"). That these threats are relevant to real-world applications is apparent from an increasing number of cyberattacks explicitly addressing industrial control systems [68]. Prominent examples are the malwares Stuxnet, Duqu, Industroyer, and Triton [14] as well as inference attacks arising from smart meters used as surveillance devices [30, 46].