Foreword One of the most mysterious areas of information security is industrial system secu- rity. No other area of information security contains that many myths, mistakes, mis- conceptions and outright lies. Information available online, while voluminous, will only lead information security professionals and industrial systems professionals to more confusion and more misconceptions--which may result in not only costly, but also life-threatening, mistakes. What raises the mystery even higher is that the stakes in the area of industrial security are extremely high. While the loss of trade secret information may kill a business, the loss of electricity generating capability may kill not just one person, but potentially thousands. And finally the mystery is solved--with this well-researched book on industrial system network security. The book had a few parts of particular interest to me. I liked that the book covers the "myth of an air gap"--now in the age of wireless, the air gap is not what it used to be and should not be assumed to be "the absolute security." I also liked that safety versus security is covered: industrial engineers might know more about the former while my InfoSec colleagues know more about the latter. Today's interconnected industrial systems absolutely need both! Finally, I also liked the book's focus on risk and impact, and not simply on following the regulatory minimum.