It is important to be aware of and take note from Ashby’s Law of Requisite Variety when addressing the problem of cyber security for a smart city.
If a system is to be stable, the number of states of its control mechanism must be greater than or equal to the number of states in the system being controlled. Ashby states the law as “variety can destroy variety”
The best explanation to how this applies can be found through Stafford Beer’s explanation video.
The threat landscape of a Smart City offers the Attacker a huge variety of opportunities through the predicted numbers of devices, sensors and systems for exploitation as well as a range of targets. As Ashby’s law and Stafford Beer describe, the system required to control another system needs an equal or greater range of variety to overcome and manage it. Thus the scale of cyber security technology, monitoring and capability must be greater in variety than the variety afforded to the Attacker.
To further explain this it is also useful to consider – Basis for the Viable System Model by Stafford Beer – as a means to help address the cyber security strategy for a smart city and the issues faced.
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