Security Violation : Access Siri when Mac is Locked

Siri in Mac OS Sierra can be accessed even when the Mac is locked. However there is no setting to turn it off, and by default it can be accessed through the lock screen. As an example, An adversary can read emails, and perform a lot of actions. In our case, when a Bluetooth device is connected, You can remotely trigger by pressing the call button for 3 seconds. It may also be possible through the audio jack, using a pair of iPhone earphones.

Bypassing OS X Security

This same issue persists on the iPhone, However Apple supports disabling Siri Access when the iPhone is locked. However, There seems to be no such option on the Mac.