Membership: PayPal Encrypted Buttons

I just signed up for the monthly WPMU plan and am wanting to use the Membership plugin because I currently use PayPal subscription buttons. My PayPal account only accepts encrypted PayPal buttons and I cannot turn that off. I have a public and private key I use to automatically generate the buttons. How would I make the Membership plugin use Encrypted PayPal buttons (even if I need to manually add some code to make it work)?