Is HTTP Public Key Pinning Dead?
I figured interesting words would probably start to trickle out about HPKP after the last month or so of talks. Opinions are split on how much damage RansomPKP and other hostile pinning attacks can do. I&#x27;m inclined to believe that it&#x27;s a big enough risk to warrant some action (such as more diligence by free certificate authorities -- the crux of the talk was rekeying at up to 20x per week enabling the attack). Others, notably Mozilla, are taking the wait-and-see approach. Google and Let&#x27;s Encrypt were the most resistant to changing anything at all.<p>Anyway, Scott Helme&#x27;s writeup did a quick and solid job of summarizing a lot of it. It&#x27;s linked from the Qualys piece, but here it is if you&#x27;d rather get to it directly: <a href="https:&#x2F;&#x2F;scotthelme.co.uk&#x2F;using-security-features-to-do-bad-things&#x2F;" rel="nofollow">https:&#x2F;&#x2F;scotthelme.co.uk&#x2F;using-security-features-to-do-bad-t...</a><p>Full Disclosure: I and buu700 (<a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;user?id=buu700" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;user?id=buu700</a>) did the AppSec Glory talk at Black Hat &#x2F; DEF CON and developed the RansomPKP attack pattern.<p>Edit for Fuller Disclosure plus added thoughts: I&#x27;d rather not see HPKP die because we&#x27;ve done some cool stuff with it over at Cyph. I&#x27;d rather see HPKP be refined with extra requirements, possibly some sort of tie-in with CAA (that little-known standard for enforcing which CAs can issue certs for your domain).<p>Speaking of CAA, we did a show of hands in both the BlackHat and DEF CON versions of the AppSec Glory talk. Five hands across thousands of attendees. That&#x27;s it.