These are 10 security things I think you should know/do about iOS11.

You can choose a passcode from 4 to 1,000,000 digits!

There is an option to automatically erase all Data after 10 failed passcode attempts!

You can temporarily deactivate the Touch ID!

Open Settings

1. Tap Emergency SOS
2. Turn on “Works with 5 Clicks”
3. Turn off “Auto Call”

Disable Lock Screen Features!

Two-Factor Authentication for Apple ID

Enable "Find my iPhone"

Disable Messages Preview

Use Safari - User/Settings Privacy

Safari includes cross-site tracking prevention, which will reduce sites like Amazon or Google from using your browsing history to suggest products in advertisements (which can be a good thing depending on your point of view). Additionally, Safari can integrate with third-party content blockers from the App Store to further reduce the advertisements you see while surfing the web.

Use a Third-Party VPN on public Wifi