WhatsApp announced this on its official Twitter page. Now, to authorize the application on a PC, you will need to go through biometric authentication.
Previously, you only had to scan the QR code to enter the application. Now, you will need to pass preliminary biometric authentication on devices running Android and on the iPhone. Only after that you can scan the QR code and get into the application.
Additional verification will be enabled on all devices by default. There is only one way to bypass it – by completely disabling biometric authentication on a smartphone.