<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><blockquote type="cite" class=""><div class="">On Jan 5, 2019, at 8:40 PM, Joshua Marpet <<a href="mailto:joshua.marpet@guardedrisk.com" class="">joshua.marpet@guardedrisk.com</a>> wrote:</div><div class=""><div dir="ltr" class=""><div class="">Any systems out there which will auto-decrypt, not based on a clock (which can be spoofed), but instead based on an event, a piece of information, a trusted info source? Something like the Long Now foundation's clock?</div></div></div></blockquote><br class=""></div><div><div class="">This is not weird at all, US Census has exactly that requirement. They have a law that requires all the census responses be secret for 70 years and then public after that. </div><div class=""><br class=""></div></div>There is no clock based system that I know of that does not require a trusted third party or a trusted group of third parties. <div class=""><br class=""></div><div class="">The group idea would be similar to the <a href="https://csrc.nist.gov/CSRC/media/Presentations/The-NIST-Randomness-Beacon/images-media/day2_demonstration_1100-1150pt1.pdf" class="">NIST Beacon</a> (which is offline at the moment due to government shutdown) that has similar services in <a href="https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=2ahUKEwiAo6ym5dnfAhWC_p8KHaMtD34QFjADegQIBxAB&url=https://beacon.clcert.cl/&usg=AOvVaw3RvRIynvzWS-KJpSZBJ-VV" class="">Chile</a> and maybe <a href="http://science.sciencemag.org/content/360/6396/1383" class="">Brazil</a>. The idea would be to use SSS to break up the key in <i class="">m</i> of <i class="">n</i> and send <i class="">n</i> pieces to different time escrow services with a statement to release in 100 years. As long as <i class="">m</i> do not collude to release the secret, the secret is safe. As long as <i class="">n-m</i> continue to operate in 100 years, your secret will be released. <br class=""><div class=""><br class=""></div><div class="">Less likely ideas would be to: </div><div class=""><ul class="MailOutline"><li class="">Encrypt with 1024 bit RSA and in 100 years it “should” be easily breakable. Ditto for AES 128. </li><li class="">Put the key on a rocket that will take 100 years to make a specific flight. </li><li class="">Use a radio to bounce a signal off a star 50 light years away.</li></ul><div class=""><br class=""></div></div><div class="">Jim</div></div></body></html>