Set a strong six-digit (or longer) passcode
Data on your iPhone or iPad is encrypted with a passcode.
Go to Settings > Touch ID & Passcode, and enter your existing passcode if you have one. If not, select Turn Passcode On, and then select Passcode Options. This gives you the option of a custom alphanumeric or numeric code or the older four-digit numeric code.
Switch off Home screen features
Don't give away free access to your locked iPhone through things like Siri.
Go to Settings > Touch ID & Passcode, and enter your passcode. Scroll down to see your lock screen access. The fewer items that are on, the better. From here, you can turn off your Today view, your wallet access, and other features, like Siri and Home Control -- and now Return Missed Calls, a new feature of iOS 11.
Set up two-factor authentication
Two-factor authentication is one of the best ways to stop hackers from accessing your data. Before Apple lets you into your account, it sends a code to a device that only you will own, which prevents someone from taking your data even with your username and password.
Go to Settings > and tap your name at the top, then go to Password & Security, then Two-Factor Authentication.
Switch off data-leaking widgets
Gone are the days when your iPhone acted as a security checkpoint. Swipe-right on your phone opens up Today View, which lets you see at a glance from your lock screen your events for the day, news, and in some cases personal information.
You can turn off each panel by swiping to the right on the Home screen (into the Today View pane), then scrolling to the bottom, and selecting Edit. From there, you can remove each panel as necessary.
Reset your app location settings
Your apps can take a lot of liberties -- especially when it comes to your data. Some apps, like Uber, sparked controversy when they used user location at all times rather than only while they were using the app. And there was no way to turn it off.
Now, your iOS 11 device gives you more granularity to prevent this kind of constant location tracking.
Go to Settings > Privacy > Location Services, then go to any app to check its location permissions. You can now set up the Uber app so that it only collects location data when you're using it -- and no other times.
Use the password manager
An in-built app friendly password manager might be iOS 11's most underrated feature. With one tap, the login fields are populated with the user's password. The password manager is protected by the user's device passcode, or Touch ID if it's enabled, to prevent others from snooping.
Change these Safari settings, stat
Safari, your mobile web browser, has several privacy settings worth exploring. Apple now puts new restrictions on how cookies can be used to personalize ads, making it tougher for advertisers to track you across websites. Apple says the intent is to ensure that users only have persistent cookies from sites they interact with while tracking data is continuously cleaned out.
Go to Settings > Safari and switch on Block Pop-ups, and prevent Cross-Site Tracking to stop advertisers from monitoring your browsing habits, and Ask Websites Not to Track Me in case they have a setting enabled. You're also safer by using the built-in Fraudulent Website Warning, which detects nefarious, phishing pages.
