Can I encrypt one question?

Hi 

I only have one sensitive item in a survey that should be securely transmitted.  Is there a way to have one question where they upload a file that can be encrypted and the rest not encrypted?

I am set up a key but I am not sure the best application to open a .key file.  Thanks

It is not possible to encrypt only one form field.

Also, please note that on Encrypted Forms uploaded files are left as they are - meaning that any file that gets submitted on your form (photo, document, etc) is left unchanged. The uploaded files are not encrypted.

More about Encrypted Forms, you can find inside of this guide:

Encrypted Forms and How to Use Them