to your <em>application/config/config.php</em>, open the file
and set:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$config</span><span class="p">[</span><span class="s1">&#39;encryption_key&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;YOUR KEY&#39;</span><span class="p">;</span>
</pre></div>
</div>
<p>You’ll notice that the <code class="docutils literal"><span class="pre">create_key()</span></code> method outputs binary data