你应该是根据不同的用户进行缓存吧!
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconusercredentialsfileusersxml.asp
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconusercredentialsfileusersxml.asp
问题针对什么不够详细,办法有很多,但是未必适合您的要求,要看实际情况