After a significant number of well publicized cybersecurity attacks on automation systems, most plant owner/operators now recognize that a cybersecurity attack is a credible risk. The ICS owners/operators must improve cyber defenses if they want to even keep up in what has become an arms race of sorts. This effort may seem overwhelming, but it is not. There have been enough successful cyberattacks over the years that hacker attack patterns have been characterized and documented. With each attack pattern, a defense against the attack has been developed and these defense requirements can be found in cybersecurity standards.
Many believe that IEC 62443-4-1 provides the strongest future impact for cyber hardened systems. That standard lists the requirements for product development and test, especially software development requirements. Like the functional safety standard IEC 61508 which has been used for decades in safety certified products, IEC 62443-4-1 lists the hardware, firmware and software design requirements needed to provide cyber hardening by design.