<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">On Thu, 15 Sep 2016 11:46 Tom Mitchell wrote:<div class=""><br class=""></div><div class=""><blockquote type="cite" class="">The physical security rules of one time pads may have changed.<br class=""><br class=""><a href="http://www.pbs.org/newshour/rundown/mit-machine-read-books-without-opening/" class="">http://www.pbs.org/newshour/rundown/mit-machine-read-books-without-opening/</a><br class=""><br class="">This may have risks when tamper evident devices for<br class="">nuclear launch code challenge response methods are considered.<br class="">The launch codes -- well that is a movie plot threat I hope.<br class=""><br class="">Sending a pre-shared secret via US mail to establish<br class="">VPN and othersecure remote office communication channels<br class="">may have gotten harder for high value government<br class="">and civilian organizations.<br class=""><br class="">This implies that nine pages deep into a onetime pad<br class="">can be read in the lab... flip it over and it is 18 pages.<br class="">With luck flash paper pads would just ignite ;-)</blockquote><br class=""></div><div class="">The reported technology is terahertz radiation. A sheet of aluminum foil each under the top and bottom covers should completely block terahertz scanning signals. In the olden days, naval code books had lead sheets in the covers to insure they would sink if thrown overboard. Wrapping all sensitive documents sent through the mail in foil may be the next thing, </div><div class=""><br class=""></div><div class="">Arnold Reinhold</div></body></html>