Messaging service WhatsApp is giving you the option to add an extra layer of security to your account with two-step verification.
WhatsApp already encrypts conversations and does all it can to ensure your data stays private. The new two-step verification feature will make it harder for other people to access your account.
Two-step verification adds an extra step when you log in to WhatsApp. First the service will send you a random passcode when you sign in, then you'll need to enter a six-digit passcode.
To turn on two-step verification, open the app and then go to Settings > Account > Two-Step Verification.
Select Enable, then enter a six-digit code when prompted. You'll also need to enter an email address for WhatsApp to use should you forget your passcode.
If you choose not to enter an email address and forget your passcode, WhatsApp will lock you out of your account for seven days. After those seven days, WhatsApp will let you reauthorize your number without the passcode, but any messages sent to you during those seven days will remain undelivered.
In other words, make the passcode something you can remember, and enter an email address in case you forget it.