Quote Originally Posted by Toned View Post
When I run my wow traffic through a proxy as expected I get prompted for my authenticator key, but not again until I change proxy servers, or disconnect from the proxy.

Some testing I did:

If I login from my home network first time I get prompted for a key.
Any other logins are straight logins no key required.
Switch to a proxy first time I get prompted for a key.
Any other logins are straight logins no key required.
Disconnect the proxy.
Sign in from home network... I get prompted for a key.

I think blizzard is caching last authenticated IP. Similar to the dialup authenticator. I could be way off, but above is what I did to make me conclude this.
This is exactly what Blizzard said 3 days ago. However, there is apparently more than just an IP address
otherwise this would be absolutely no different than the dial-in authenticator.

Blizzard tweeted this, this, and this, they're obviously not going to give away all the tricks on what they're
doing on their end.