switch ( tagged.getTagNo() ) {
            case 0:// Kerberos version
                ASN1Integer tktvno = ASN1Util.as(ASN1Integer.class, tagged);
                if ( !tktvno.getValue().equals(new BigInteger(KerberosConstants.KERBEROS_VERSION)) ) {
                    throw new PACDecodingException("Invalid kerberos version " + tktvno);
                }
                break;
            case 1:// Realm