HPKP can be either TOFU or preloaded. Google maintains a preload list that is included with Chrome, Firefox, Opera, Safari, IE 11 and Edge, but that is not a sc

HPKP can be either TOFU or preloaded. Google maintains a preload list that is included with Chrome, Firefox, Opera, Safari, IE 11 and Edge, but that is not a scalable solution for the future.