This is actually a “Reverse Two-Factor Verification” of what we knew before.
WhatsApp has been continuously updating its messaging app in beta stages where the feature called “Two-step verification” has been added in the latest beta version or may be one or two builds ago.
Recently WhatsApp added the video calling feature in the app, following that the most recent addition is the two-step verification that will let users secure their account with a six-digit passcode. With this two-step verification enabled, in addition to standard registration via mobile number will require you to enter the passcode set for the number.
Usually platforms including your mail account providers or other account registrations provide a two-factor authentication in a way that 1, you need to sign in to your account which 2, sends a verification code on your registered mobile number which 3, is needed to provide during the sign in process.
Unlike above flow of 2-step verification, once enabled in WhatsApp, upon registering your number on a new device will require you to provide the passcode you set previously before you could register on the phone.
How does it work actually?
WhatsApp Two-step verification is an optional feature that you enable by going through WhatsApp > Settings > Account > Two-step verification > Enable. You will give a passcode that will be used for 2-step verification. You can also provide an email address that will be used to disable the feature in case you forget your passcode.
WhatsApp has listed FAQ for Two-Step Verification as well; consider below.
If you have two-step verification enabled, your number will not be permitted to reverify on WhatsApp within 7 days of last using WhatsApp without your passcode. Thus, if you forget your own passcode, but did not provide an email to disable two-step verification, even you will not be permitted to reverify on WhatsApp within 7 days of last using WhatsApp. After these 7 days, your number will be permitted to reverify on WhatsApp without your passcode, but you will lose all pending messages upon reverifying – they will be deleted. If your number is reverified on WhatsApp after 30 days of last using WhatsApp, and without your passcode, your account will be deleted and a new one will be created upon successfully reverifying.
Currently the feature is available in the latest beta version of WhatsApp v 2.16.346 which would be graduated soon to Play Store. If you have joined WhatsApp’s beta tester program on Play Store, you will be able to download the beta version directly from Play Store.
However you can always download the WhatsApp beta app and install manually. Pick up the latest version available at apkmirror that might be newer than 2.16.346