VirtueMart and Paypal: encryption

[Philistine]

I'm in the process of setting up my first shopping cart using VirtueMart and I aim to offer payments via PayPal. I have previously used Open SSL to encrypt the PayPal buttons before posting and am wondering if this is still necessary with VirtueMart. I see the Payment Extra Info box doesn't encrypt and I also see that the data posted is not available through the source at the browser so my question is: how secure is the communication between VirtueMart and PayPal?