<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On May 4, 2017, at 12:00 AM, Benjamin Kreuter <<a href="mailto:brk7bx@virginia.edu" class="">brk7bx@virginia.edu</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">On Tue, 2017-05-02 at 19:10 -0400, Viktor Dukhovni wrote:</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class=""><blockquote type="cite" class="">On May 2, 2017, at 2:50 PM, Phillip Hallam-Baker <phill@hallambaker<br class="">.com> wrote:<br class=""><br class="">It isn't really the case that control systems were expected to last<br class="">a hundred years.<br class="">Most would be ripped out and replaced on a regular basis.<br class=""></blockquote><br class=""><a href="https://www.nytimes.com/2017/05/01/nyregion/new-york-subway-signals.h" class="">https://www.nytimes.com/2017/05/01/nyregion/new-york-subway-signals.h</a><br class="">tml<br class=""><br class=""> On a recent evening, Mr. Habersham walked along the train tracks<br class="">near 34th Street<br class=""> in Manhattan as workers replaced antiquated switches and cables. A<br class="">signal system<br class=""> should last about 50 years, he said, but the one that guides<br class="">trains through this<br class=""> slice of Manhattan has been in place for about 80.<br class=""></blockquote><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">That is not quite right; while the design of that equipment is decades</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">old, most of the parts have to be replaced periodically. Those</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">machines are electromechanical and they have all the failures one would</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">expect of gears, levers, and vacuum tube relays.</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""></div></blockquote></div><br class=""><div class="">And there is an overlay of Siemens PLCs (same ones that Stuxnet attacked) which is probably not upgraded as often as people on this list expect.</div><div class=""><br class=""></div><div class="">That said, what about any mechanical system that is designed for 50 years with computer control? At this time, the IoT market assumes low cost throw away things. This is not universal. Stuff deployed on a light pole is IoT but will not be low cost or throw away. </div><div class=""><br class=""></div><div class="">IoT without the ability to upgrade the software is a toy and if it is not a toy there should be repercussions for the vendor.</div><div class=""><br class=""></div><div class="">Case in point that I have (indirect) experience with. The original 747 inertial guidance computer was a GM Delco Magic computer, which in 1960 was transistors and core memory and monitored a gyro stabilized mechanical platform. That computer was operational for ~40 years before it was replaced by a more “current” inertial guidance computer using solid state sensors. The reason it was replaces was not the obsolescence of the computer, but the sensitivity of the gyro stabilized platform. During that time, the boards were replaced with newer technology while maintaining the same board level functionality. </div><div class=""><br class=""></div><div class="">Another important point is that there has never been a commercial crypto system that has lasted more than ~40 years (Vernon cipher aside).</div><div class=""><br class=""></div><div class=""><br class=""></div></body></html>