This letter develops a fog computing-based encrypted control system in a practical industrial setting. The developed system conceals controller gains and signals over communication links using multiplicative homomorphic encryption to prevent eavesdropping attacks. Experimental validation confirms the feasibility of position servo control for the motor-driven stage with the developed system in terms of performance degradation, parameter variation, and processing time. The developed system inherits its stability regardless of whether plant parameters fluctuate or not even after the controller gains and signals are encrypted. Furthermore, although processing time becomes longer by increasing a key length of encryption, degradation of control performance is improved simultaneously.

中文翻译：

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基于雾计算的加密控制系统的开发与检验

这封信在实际工业环境中开发了一种基于雾计算的加密控制系统。开发的系统使用乘法同态加密隐藏控制器增益和通信链路上的信号，以防止窃听攻击。实验验证证实了在性能退化、参数变化和处理时间方面，使用开发的系统对电机驱动平台进行位置伺服控制的可行性。即使在控制器增益和信号加密后，无论工厂参数是否波动，开发的系统都继承其稳定性。此外，虽然通过增加加密的密钥长度而使处理时间变长，但同时改善了控制性能的劣化。