求翻译：⑵ 从源站点发出的安全令牌能被所有源站点信任的目标站点查看，无需在源站点和指定的目标站点之间事先建立安全通道，而只需事先协商好加密和数字签名处理的密钥。这样，这两类站点间的独立性就得到增强，提高了系统的灵活性和可配置性。是什么意思？

(2) from the source site security token can be issued by the trust of all the source site of the target site viewing, without the prior establish a secure channel between the source site and the designated target site, while just prior consultations, the key of good encryption and digital signature

(2) from the source site's security token can be all of the source site is the goal of confidence-buildin