If you ever connected your computer to a computer before you know iOS prompts you to "Trust" the computer and enter your passcode to confirm. According to Apple, trusted computers can "sync with your iOS device, create backups, and access your device's photos, videos, contacts, and other content." That's a lot of permissions to hand off, especially if the computer is not your main laptop or desktop.
There are quite a few reasons why you'd want to untrust a computer. Maybe you had a friend load up your iPhone with some cool ringtones they created in iTunes. Perhaps you trusted a computer by mistake because you just wanted a quick charge. Or, maybe it was a public computer that used Image Capture on. Either way, if it's not your primary computer, you should trust it in a case somebody ever gets a hold of your iPhone and has access to the trusted computer.
Also, there's "trustjacking." Once you've authorized a computer to access your iPhone ̵1; even if the "computer" just looks like a normal charging station you'd find out in public areas – your iPhone can be attacked while connected to the same Wi-Fi network as The computer, leading hackers to install malware, spy on your usage, take backups of your photos and call logs, and perform just about anything else you can think of.
Un-Trusting Devices Your iPhone computer is not hard, even though you are able to pick and choose which computers to untrust – you have to disengage from all of them all at once.
There are three options for untrusting computers, listed here in order of least annoying to most annoying. For example, Option 1 will not be too disruptive to you, but Option 2 will require more work to get your iPhone back to its previous state. And with Option 3, you'll need to set up your iPhone all over again. All of these have positive aspects, side effects that you can find beneficial, so be sure to read through to the end of which is right for you.
Option 1: Reset Network Settings
This is by far the least intrusive way to untrust a computer. By performing this method, all you really need to do is re-enter the credentials for Wi-Fi networks you commonly connect to. It's also beneficial since your iPhone will no longer connect to the myriad of unsecured public networks you potentially accrued along the way. However, this will also reset cellular settings and VPN settings.
First, open up your Settings app, then go to "General." From there, tap "Reset," then "Reset Network Settings."
After you do, tap "Reset Network Settings" on the confirmation prompt, and your device should restart. You should immediately go to your Wi-Fi settings after this, if you are logged out of any network you are currently connected to.
If you have customized certain aspects in the "Cellular" section in Settings or had a VPN configuration set up, you'll need to redo those as well
Option 2: Reset Location & Privacy Settings
Reset "Location & Privacy" settings are a more intrusive way to untrust a computer. Optionissions This includes location, camera, photo, contacts … everything. If you have some apps that you regret giving certain permissions to, this could be a good catch-all to bring everything back to center.
The process to do this is almost identical to the one above. Instead of tapping "Reset Network Settings," though, hit "Reset Location & Privacy." Need to enter your passcode again and select "Reset Settings" after you do so to complete the process. Your device may or may not restart.
Every time you open the app, though, you'll need to re-grant the permissions that you previously gave it before (or choose not to grant it if that's the case). It can be child or annoying, so go with Option 1 if you're unsure if you want the hassle of all this.
Option 3: Restore to Factory Settings
Restoring your iPhone to factory settings is the most damaging of these options. It'll just wipe your iPhone with your contacts, photos, files, apps, and everything else. Before you choose the option from the "Reset" menu – titled "Erase All Contents and Settings" – your iPhone will prompt you to back up everything on iCloud so you can restore it later.
I did not suggest it unless you were planning to reset your iPhone to factory settings. It's just too much work to get your iPhone back up to snuff, less trusted computers.
When it comes down to it, whichever method you choose to untrust computers really comes down to each one's side effects. If you want to save any of your saved connections, you might want to ship Option 1 in favor of Option 2, and just deal with reaccepting permissions for your apps.
It would be nice if Apple allowed us to manually untrust computers rather than through one of these three roundabout methods. Until then, you just need to pick one's least disruptive to your iOS ecosystem.
This article was produced during Gadget Hacks' special coverage on smartphone privacy and security. Check out the entire Privacy and Security series.