<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="">On Thu, 12 Sep 2019 10:35:27<br class="">Jerry Leichter <<a href="mailto:leichter@lrw.com" class="">leichter@lrw.com</a>> wrote:<div class=""><br class=""></div><div class=""><div dir="ltr" class=""><blockquote type="cite" class=""><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">...But consider: If I can slip a change into the hardware, why attack the RNG? I can attack anything at all! In fact, there are already published examples - among many - of attacks on Ethernet interfaces such that simply seeing a particular series of bits in the input causes it to do arbitrary nasty things - like sending the contents of selected memory locations to an attacker. ...</span></div></blockquote><div class=""><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div></div></div><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">An attack that weakens the RNG has unique advantages to the attacker. Once in place it is almost impossible to detect. It requires no back channel to reveal sensitive information. It is immune to software updates, as long as they do not change the source of random numbers. It’s a very economical attack. It potentially opens all of the victims encryption to the attacker. A gift that keeps on giving. </span></div><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div dir="ltr" class=""><blockquote type="cite" class=""><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">... In fact, we currently don't *have* any techniques for defending against such attackers, beyond the physical-world techniques of maintaining visibility into all of the supply chain. That was, at one point, something available to, say, the US military. Today, it's unlikely even the US military can afford it - a major concern, given how much the US military relies on computers. Perhaps the NSA can, for relatively limited numbers of chips that it can build in its own "black" fabs. ....</span></div></blockquote><div class=""><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div></div></div><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">Here is a link that discusses current US DoD efforts to address the supply chain problem:</span></div><div dir="ltr" class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span><a href="https://www.acq.osd.mil/se/initiatives/init_micro.html" class="">https://www.acq.osd.mil/se/initiatives/init_micro.html</a></div><div dir="ltr" class=""><br class=""><div class=""><br class=""><div dir="ltr" class="">Arnold Reinhold </div></div></div></div></body></html>