https://www.theregister.co.uk/2019/04/10/google_cloud_roundup/

People with suitably modern Android phones can now use their handsets as a hardware security key to safeguard both their Google Accounts and Google Cloud accounts.

The ads and compute-time rental biz announced the change at Google Cloud Next '19 in San Francisco, in conjunction with some hand waving about a variety of other security tools tied to the Google Cloud Platform.