Instead of the traditional password punched in at sign-in, the app will use what's called the Yahoo Account Key feature. The company said it will take "user convenience and security to the next level."
Account Key uses push notifications to provide a faster way to sign into email using your mobile device. Once a user has linked the Yahoo account with the smartphone app, he or she will receive a push notification upon trying to sign in on the web. The user just Has to verify or deny the access on the phone.