Whatsapp has made available a two-step verification for its over a billion users. A two-step verification provides an additional layer of security and makes it harder for attackers to gain access to a person’s devices and online accounts, because knowing the victim’s password alone is not enough to pass the authentication check.
It is optional on WhatsApp and can be enabled by going to the Settings, clicking on “Accounts” and selecting “two-step verification” in the app. When you have two-step verification enabled, any attempt to verify your phone number on WhatsApp must be accompanied by the six-digit passcode that you created using this feature.
Upon enabling this feature, you can also optionally enter your email address. This email address will allow WhatsApp to send you a link via email to disable two-step verification in case you ever forget your six-digit passcode, and also to help safeguard your account. WhatsApp does not verify the email provided so you have to be careful to input the right one.
If you forget your own passcode, but did not provide an email to disable two-step verification, 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.
To help you remember your passcode, WhatsApp will periodically ask you to enter your passcode. There is no option to disable this without disabling the two-step verification feature.