Up until now, users could protect their Chromebook by entering either using their Google account password or by using a paired smartphone to unlock it. There’s now a third option: a simple personal identification number.
In a recent Google + post, Google developer François Beaufort outlined how to use the feature:
All you have to do is enable the flag chrome://flags/#quick-unlock-pin, restart Chrome, and go to Chrome Material Design settings page for now to set up your Lock Screen PIN in the new "Screen Lock" section. When it's done, lock your screen with + L and enjoy the new unlock experience!
He noted that the feature is still experimental, but that it should make things slightly easier for users.
According to OMG! Chrome, the feature is part of the latest Canary Build for the operating system, and it will allow users to input a four-digit PIN rather than their entire Google account password. This is only used for the lock screen and won’t replace the initial login to start up your computer. If you have a long, complicated password, this would make it easier to get back to work.