<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><span style="font-family:arial,sans-serif">On Sat, Dec 31, 2016 at 1:11 AM, Adrian Tymes </span><span dir="ltr" style="font-family:arial,sans-serif"><<a href="mailto:atymes@gmail.com" target="_blank">atymes@gmail.com</a>></span><span style="font-family:arial,sans-serif"> wrote:</span><br></div><div class="gmail_extra"><div class="gmail_quote"><br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><span class="gmail-">On Fri, Dec 30, 2016 at 10:01 PM, John Clark <<a href="mailto:johnkclark@gmail.com">johnkclark@gmail.com</a>> wrote:<br></span></blockquote><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"></blockquote> <br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><font size="4"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​>> ​</div>But why couldn't NIST sign it? ​</font><div class="gmail_default" style="font-size:large;font-family:arial,helvetica,sans-serif;display:inline">I send my video to NIST and a few seconds later they send me a file signed with NIST's private key that says "we received your video ​and made this hash of it at time X". Then if somebody produces a different version of the video with a time stamp later than X on it I can produce the signed hash of the earlier video proving the later one must be </div><span style="font-size:large;font-family:arial,helvetica,sans-serif">phony<div class="gmail_default" style="display:inline">​;​</div> provided <div class="gmail_default" style="display:inline">​of course ​</div>it<div class="gmail_default" style="display:inline">​ is</div> generally agreed that NIST is honest.<div class="gmail_default" style="display:inline">​ </div></span></blockquote></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><br></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><br></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​> ​</div>That's a confusion between "could" and "does".<br></blockquote><div><br></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><font size="4">​I'm not confused, I realize ​NIST doesn't do that but there is no reason they, or some other trusted third party, couldn't do that.</font></div></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​> ​</div>there would be no<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​ ​</div>obvious reason why NIST should be more trusted to do this</blockquote><div><br></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​<font size="4">Well, we already trust them to tell us how long a inch is and how much a pound weighs and how many seconds there are in a year and when to put in a leap second; and you have to trust somebody.</font></div></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"><font size="4"><br></font></div></div><div><font size="4"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">John K Clark ​</div> </font></div><div><br></div><div><br></div><div> </div></div></div></div>