O ur iPhones are at the center of so much that we do. As such, it's wise to take measures to ensure that no one can access the personal data it stores, such as credit cards, emails, and photos. That way, even if your iPhone falls into the wrong hands, you'll be protected.
SETTING UP TOUCH ID & PASSCODE
If you have an iPhone 5s or later, the Home button houses a Touch ID fingerprint sensor, which you can use to unlock your phone, authenticate purchases from the iTunes and App Store, access third-party apps, and make transactions with Apple Pay (if you have the iPhone 6 or 6 Plus).
To use the sensor, go to Settings > Touch ID & Passcode. You'll be prompted to enter your passcode if you have one; otherwise, you'll be asked to set one up. Under Fingerprints, tap Add a Fingerprint to enroll as many as five fingers. You'll be prompted to lift and press your finger until the process is complete. Tap the entry to rename it. Touch ID isn't an all-or-nothing deal—you can specify which services you'd like to use it for in Settings. Many third-party apps now support Touch ID too, which you can enable in individual app's settings.
SETTING A PASSCODE
To set up a 4-digit code, scroll to Touch ID & Passcode in Settings (or simply Passcode on an iPhone 5 or older). Tap Simple Passcode, then Turn Passcode On at the top of the screen. To set a more advanced passcode, disable Simple Passcode before tapping Turn Passcode On. You can also generate a randomized password using Wolfram Alpha. Just activate Siri and say “Wolfram password,” and it will generate random mixes of numbers and lower- and uppercase letters. If you don't have Touch ID enabled, you can customize how quickly your phone will lock by tapping Require Passcode.
TURN ON FIND MY IPHONE
Another security service from Apple is Find My iPhone, which helps you track down a misplaced or stolen device. To enable it, go to Settings > iCloud > Find My iPhone. Then, if you can't find your device, you can sign in to icloud.com or to the app on an iOS device to see the location of your device on a map. Select the device you're looking for and then tap Actions. Here you'll see a few options—tap Play Sound to make your device ring, activate Lost Mode to lock your device and display a message on the screen, or tap Erase iPhone to erase all data from the device. Choose the last option if you've given up your search but want to protect your information.