hich ensures that no untrusted party
  forces the shared secret to a known constant. If a protocol requires
  contributory behaviour, compare the output of
  <b class="Fn" title="Fn">crypto_x25519</b>() to an all-zero buffer using
  <a class="Xr" title="Xr"                href="../crypto_verify32.html">crypto_verify32(3monocypher)</a>;
  abort the protocol if the output and the all-zero buffer are equal.
<div class="Pp"></div>
Do not use the same secret key for both key exchanges and signatures. The public
