session.cookie_secure不保存

I am using sessions to create temporary file download links. Every time a new request is made, the sessions reset. I found a thread talking about turning on session.cookie_secure. But whenever I try setting it to on or 1, it won't save.

Here is what I tried in the php file:

• ini_set('session.cookie_secure', '1');
• @ini_set('session.cookie_secure','1');
• @ini_set('session.cookie_secure','On');

Here is what I tried in the php.ini file:

• session.cookie_secure = 1
• session.cookie_secure = on

Am I doing something wrong? What should I do to turn on session.cookie_secure? Is there something I could do instead of setting session.cookie_secure?