it's a pretty neat and simple idea: Kill HSTS through NTP by sending victims PC into the future. https://www.blackhat.com/docs/eu-14/materials/eu-14-Selvi-Bypassing-HTTP-Strict-Transport-Security-wp.pdf Same should work for HPKP. The idea of setting some security feature through a header needs a revisit. The solution would be to have a more reliable PC time. How do we do that? See https://www.blackhat.com/docs/eu-14/materials/eu-14-Selvi-Bypassing-HTTP-Strict-Transport-Security-wp.pdf