<p>The term you are looking for is "cross-posting".  It is a little bit ambiguous, but the general consensus is that it is inappropriate.  This topic has been discussed before on meta.CV; see these threads:  </p>

<ul>
<li><a href="https://stats.meta.stackexchange.com/q/1880/7290">Is the help 'misinformed' on the question of cross-posting?</a>,  </li>
<li><a href="https://stats.meta.stackexchange.com/q/1948/7290">Cross-posting in CV and math.SE tends to become an epidemic</a>, and  </li>
<li><a href="https://stats.meta.stackexchange.com/q/941/7290">Posting the same question on other statistics forums in addition to CV</a>.  </li>
</ul>

<p>Your situation may be different, though.  The typical problem is that someone asks an identical statistics question here and on math.SE (which has a <code>[statistics]</code> tag and small set of dedicated followers), or an R / statistics question here and on SO. Your description is too vague for me to know for sure, but I wonder if the statistical and cryptographical aspects are different aspects of the question.  If you want a statistical perspective on something, and a cryptographical perspective on it as well, that strikes me as acceptable.  You aren't just fishing for a faster answer, or trying to find someone who'll do your homework for you, and the answers wouldn't provide duplicate information across the SE system.  </p>
