Securing forms submitting to a different domain

I want to secure some forms that 开发者_开发技巧are placed on third party sites and submit to our little in house affiliate app.

What is involved to encrypt forms between sites? Is SSL on the receiving domain sufficient? or does the page the form sits on need to be https too?

Essentially, you could do it two ways. One simple way is to use HTTPS and but thats as long as both can be HTTPS. They must also both have SSL certificates.

Another way is to POST the forms locally encrypt/secure the data, then do another request over to the other domain where you decrypt it.