Case sensitive in list search whith encrypted field

[startpoint]

Based on this commit
https://fabrikar.com/forums/index.php?threads/data-encryption.47960/page-2#post-249400
the search is still case sensitive.
If I change function

    public function encryptFieldName(&$key)
    {
        if ($this->encryptMe())
        {
            $db     = FabrikWorker::getDbo();
            $secret = $this->config->get('secret');
            $matches = array();
            if (preg_match('/LOWER\((.*)\)/', $key, $matches))
            {
                $key = 'LOWER(CONVERT(AES_DECRYPT(' . $matches[1] . ', ' .     $db->q($secret) . ') USING utf8))';
            }
            else
            {
                $key = 'LOWER(CONVERT(AES_DECRYPT(' . $key . ', ' . $db->q($secret) . ') USING utf8))';
            }
        }
    }

the search work properly.
How can I use it even after update?