<story><title>Drug cartels use dollar bill serial numbers as random keys for delivery receipts</title><url>https://twitter.com/arawnsley/status/1151849118790246402</url></story><parent_chain></parent_chain><comment><author>carrozo</author><text>Banksy uses a similar system to authenticate his work:&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;boingboing.net&amp;#x2F;2019&amp;#x2F;03&amp;#x2F;31&amp;#x2F;di-faced-note.html&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;boingboing.net&amp;#x2F;2019&amp;#x2F;03&amp;#x2F;31&amp;#x2F;di-faced-note.html&lt;/a&gt;</text></comment>
<story><title>Drug cartels use dollar bill serial numbers as random keys for delivery receipts</title><url>https://twitter.com/arawnsley/status/1151849118790246402</url></story><parent_chain></parent_chain><comment><author>PeterisP</author><text>The key part here seems to be protection against all kinds of message interception attacks - if I listen in on the conversation and hear that the code is 12345678, then I can&amp;#x27;t easily create a dollar bill with that code on it, and probably even the FBI can&amp;#x27;t do it quickly enough for it to be useful.</text></comment>