<story><title>Declassified Cold War code-breaking manual on solving &apos;impossible&apos; puzzles</title><url>https://phys.org/news/2021-05-declassified-cold-war-code-breaking-manual.html</url></story><parent_chain></parent_chain><comment><author>azalemeth</author><text>It&amp;#x27;s worth saying that the book isn&amp;#x27;t &lt;i&gt;entirely&lt;/i&gt; declassified. 18 out of 84 sections (including quite a few &amp;quot;Further remarks&amp;quot; or &amp;quot;Final remarks&amp;quot; sections) are completely whited out by the censor&amp;#x27;s box.&lt;p&gt;Also, the actual PDF is here: &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.governmentattic.org&amp;#x2F;39docs&amp;#x2F;NSAmilitaryCryptalyticsPt3_1977.pdf&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.governmentattic.org&amp;#x2F;39docs&amp;#x2F;NSAmilitaryCryptalyti...&lt;/a&gt;</text></comment>
<story><title>Declassified Cold War code-breaking manual on solving &apos;impossible&apos; puzzles</title><url>https://phys.org/news/2021-05-declassified-cold-war-code-breaking-manual.html</url></story><parent_chain></parent_chain><comment><author>westcort</author><text>My grandfather worked with Lambros and shared an amusing booklet from him called &amp;quot;A short list of even primes,&amp;quot; which is a single digit: 2 (with a long  and humorous introduction). It is not classified (obviously) and I will try to get around to sharing it on here at some point in the future.</text></comment>