Old logo of the <a href="https://en.wikipedia.org/wiki/American_Cryptogram_Association" class="extiw" title="w:American Cryptogram Association">American Cryptogram Association</a> (<a rel="nofollow" class="external free" href="http://cryptogram.org/">http://cryptogram.org/</a> ), displaying a Spartan <a href="https://en.wikipedia.org/wiki/Scytale" class="extiw" title="w:Scytale">Scytale</a>.
American Crpytogram Association (ACA)
Louis Kruh (1989): "The Heraldry of Cryptology", <i>Cryptologia</i>, Oct 1984 &amp; Jan 1989 <a rel="nofollow" class="external autonumber" href="http://www.asalives.org/ASAONLINE/herald01.htm">[1]</a>, <a rel="nofollow" class="external autonumber" href="http://www.asalives.org/ASAONLINE/hfig15.gif">[2]</a>