Ensuring the security of industrial control systems is hardly a new topic. The earliest users of modern control systems in power stations and chemical plants saw the need to protect access to vital control functions from unauthorized use. Similarly, in industries such as fine chemical or pharmaceutical
where the process is the product, manufacturers have always sought to protect the secrets of their unique processes from the prying eyes of industrial spies. This white paper by ARC describes how the Siemens AG PCS7 Security Concept bundles key security measures in seveal specific areas to create a deep hierarchy of security known as defense in depth.