public function removeTrustRoot($identity, $trustRoot) {
		assert('is_string($identity)');
		assert('is_string($trustRoot)');

		$trs = $this->getTrustRoots($identity);

		$i = array_search($trustRoot, $trs, TRUE);
		if ($i === FALSE) {
			return;
		}
		array_splice($trs, $i, 1, array());
		$this->saveTrustRoots($identity, $trs);
	}