The November 2013 issue of IEEE Computer magazine has an article titles “Does security trump reliability?” The question of security vs reliability/safety is a critical one for industrial control systems (ICSs). For ICSs, security and reliability are NOT equals - reliability and safety MUST win or the system doesn’t work and the hackers have won without even trying. The real question is how close can the trade-off be made between reliability and security.
The title of my book is Protecting Industrial Control Systems from Electronic Threats. Since reliability must win, it becomes “rocket science” to protect these systems. The trade-offs between reliability/safety and security make it rocket science as so many existing IT security solutions cannot be used without impacting the performance of the ICSs.
The question of security vs reliability is also one of the drivers for the International Society of Automation (ISA) needing to develop standards for ICS cyber security (the ISA99/IEC62443 set of standards of which I am the Managing Director).
Considering the negative impact security has had on control system reliability, you might find the summary of the recent ICS Cyber Security Conference held at Georgia Tech to be of interest - www.controlglobal.com/unfettered. One of the case histories discussed was a security patch causing the LOSS OF CONTROL of a large industrial turbine providing power to a large industrial complex! This case led to significant discussions concerning the issues involved in implementing security (in this case patches) without impacting the reliability of the systems. One of the major drivers for the ICS Conference over the past 13 years has been to improve the understanding between the ICS and IT communities as they have the precise disparate goals as the above question – IT is focused on security and ICS focuses on reliability and safety.
I am currently working with the ONLY utility in the US willing to be a test bed for evaluating ICS cyber security solutions for RELIABILITY! The questions are why is this the only one and why isn’t there more participation.
The question of security vs reliability/safety really goes to the heart of one the major differences between and IT and ICSs and must be correctly answered if lights are to remain on, water flowing, etc.