public Data dereference (URIReference uriRef, XMLCryptoContext context) throws URIReferenceException {
String uri = null;
try{
if(uriRef instanceof DOMURIReference ){
DOMURIReference domRef = (DOMURIReference) uriRef;
Node node = domRef.getHere ();
if(node.getNodeType () == Node.ATTRIBUTE_NODE){
uri = uriRef.getURI ();
return dereferenceURI (uri,context);
}else if(node.getNodeType () == Node.ELEMENT_NODE ){
if("SecurityTokenReference".equals (node.getLocalName ())){