ch saves the value of <i>q</i> and this must be used for FIPS186-4. If key validation is required, users should be aware of the nuances associated with FIPS186-4 style parameters as discussed in <a href="#DH-and-DHX-key-validation">&quot;DH and DHX key validation&quot;</a>.</p>

<h2 id="DH-and-DHX-domain-parameters">DH and DHX domain parameters</h2>

<p>In addition to the common FFC parameters that all FFC keytypes should support (see <a href="../man7/EVP_PKEY-FFC.html">&quot;FFC parameters&quot; in EVP_PKE