Working with forms

I have Adobe Acrobat 8 Professional. I created a form with an email submit button. This form has been posted on my company's website. The form needs to be able to be opened and completed by all users. However, the users completing this form will be entering personal information, such as SS#s. Therefore, I need to protect the form when it is being submitted by email. I am thinking I want to set protections that will encrypt the information and only be able to be un-encrypted by the Admissions Director, which is to whom the form is submitted when you click the "submit" button.

Please help with step-by step instructions. How can I accomplish this?