Whatsaap now have two ways Verification

Background Audio Play back
You can now play Audio messages in the background. Previously, you had to keep WhatsApp open and stay within the conversation to hear any voice message received in it. But now reverse is the case, you switch to other conversation, apps etc as long as the audio message isnt finish, it will keep playing.
2 step Authentication
Though weve been waiting for this to manifest and now, we have WhatsApp 2-factor authentication. This new features has gone live on the latest beta version of whatsapp (2.16.341 and above, maybe even earlier).
Go to account settings in WhatsApp, youll see a new Two-step verification option. Tap it to get to a screen that explains what 2-step verification is and get the option to enable it.
Enter a 6-digit passcode that youll be asked for each time you try to register your phone number with WhatsApp, and confirm it. Youll also need to give an email address thatll be used to reset your passcode should you forget it.
Once thats done, two-step verification will be active on your phone number. No one will be able to activate WhatsApp with the same phone number unless they have the passcode or access to the email account to reset it.
If you are not a beta tester, seat and wait for the updates to hit Google playstore.