[Nimi]

Fascinating. I still feel I'm missing something basic here: If Microsoft, Google and Mozilla announce they're not going to accept any particular crypto primitive two years from now, and this time there won't be any exceptions, CAs and websites just have to abide, don't they?

[nl]

The browsers say what they accept, the server says what it provides and something in the intersecting set will be used.

If (as a random example that didn't annoy me at all for 2 years) a website also needs to support SmartTV devices which only accept obsolete certificates then your server has to either break them or not.

[Natanael_L]

Then a bunch of big companies announce they'll use another browser to be able to keep using it

[Nimi]

Another browser beside Chrome, Firefox and IE? OK, so Symantec announces that they will only use Opera. Even then, they have to deal with their customers, website operators who need a certificate trusted by the big 3 browsers, leaving. In fact, now that Let's Encrypt certificates are free, it seems like this is the Symantec CA's worst nightmare.

[Natanael_L]

Not CA:s, but clients like banks