http_referer lost using https

Question

Picture two web pages, both viewed using https. They reside on different domains.

How can I (reasonably) ensure that someone arriving at my page came via a hyperlin

Answer 1

If you've got no control over the referring site you are out of luck.

Sniff the referrer if you can, and if it's not present throw up a landing page that says "click here go to site A so you can come back here".

Additionally, spend some time working on a more robust method of accessing your 'secure' site.