All forms support SSL on JotForm. You just have to change "http://" to "https://"
Example: Let's take a regular JotForm form:
Then change "http://" to "https://":
If you would like to embed a secure form on your site you should just change "http://" to "https://" on the form code and that will also be submit securely.
However, if you do not have a security certificate on your web site, the user would not see a lock icon on their browser on the form page. So, you should probably just link to the form URL directly.