Is authkey still used?

As the title says, I know the authkey isn’t used for workshop anymore, but is it used for anything?
I’ve had a bunch of IP’s being unable to connect to Steam servers when using certain Authkey’s for the following 48 hours, almost like they’re being timed out or blacklisted by Valve for using that authkey?

For now I’ve stopped authkeys being put into the command line, but I wanted to know if there is any reason someone would need their authkey anymore?

Cheers

Oh, I didn’t know I didn’t need an auth key in my startup, but yeah I wonder what else uses it?

No, they are completely ignored by the game since a few months back.

I’ve had a bunch of IP’s being unable to connect to Steam servers when using certain Authkey’s for the following 48 hours, almost like they’re being timed out or blacklisted by Valve for using that authkey.

Is this just me making unrelated correlations?
Since I stopped putting the authkeys in the commandlines this issue stopped, and I can totally reproduce it when I use their authkey on an IP :s

Unless you run very outdated version of the game server, the authkey launch option IS COMPLETELY IGNORED BY THE GAME.

[editline]12th November 2017[/editline]

It was changed on April 17 2017