Yes, Exede is SHA-256 compatible - this site uses an SHA-256 security certificate. From a user perspective, it's a matter of whether or not the browser is SHA-256 compatible and all modern browsers are.
Paypal may simply be referring to servers where a vendor web site is hosted that has been integrated with Paypal.
SHA-256 is simply a secure hashing algorithm used for endpoint to endpoint encryption having little to do with the ISP layer.
I use Firefox, Safari, Chrome and Opera... on a iMac and for some reason I cannot get Paypal.com to load up on any of them. Never had this problem before (10 yrs) so something is up. Maybe it's because i'm of my Liberty Pass status as of last night but I've not had this problem before, either. Not being able to get into my Paypal is a disaster since i am an online seller ! I need to make this better fast as I have to print out shipping labels today... yikes !