You do bring a good point. Maybe outlandish, but see my sibling comment (https://news.ycombinator.com/item?id=28578832 https://news.ycombinator.com/item?id=2857

You do bring a good point. Maybe outlandish, but see my sibling comment (https://news.ycombinator.com/item?id=28578832 https://news.ycombinator.com/item?id=28578832) where the server overhead for rejecting invalid packets which the attacker made for free goes down to performing a hash.