privacyguides.org/docs/os/ios-overview.md
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Co-authored-by: Redoomed <161974310+redoomed1@users.noreply.github.com>
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iOS Overview simple/apple iOS is a mobile operating system developed by Apple for the iPhone.

iOS and iPadOS are proprietary mobile operating systems developed by Apple for their iPhone and iPad products, respectively. If you have an Apple mobile device, you can increase your privacy by disabling some built-in telemetry features, and hardening some privacy and security settings which are built in to the system.

Privacy Notes

iOS devices are frequently praised by security experts for their robust data protection and adherence to modern best practices. However, the restrictiveness of Apple's ecosystem—particularly with their mobile devices—does still hamper privacy in a number of ways.

We generally consider iOS to provide better than average privacy and security protections for most people, compared to stock Android devices from any manufacturer. However, you can achieve even higher standards of privacy with a custom Android operating system like GrapheneOS, if you want or need to be completely independent of Apple or Google's cloud services.

Activation Lock

All iOS devices must be checked against Apple's Activation Lock servers when they are initially set up or reset, meaning an internet connection is required to use an iOS device.

Mandatory App Store

The only source for apps on iOS is Apple's App Store, which requires an Apple ID to access. This means that Apple has a record of every app you install on your device, and can likely tie that information to your actual identity if you provide the App Store with a payment method.

Invasive Telemetry

Apple has historically had problems with properly anonymizing their telemetry on iOS. In 2019, Apple was found to transmit Siri recordings—some containing highly confidential information—to their servers for manual review by third-party contractors. While they temporarily stopped that program after that practice was widely reported on, the problem wasn't completely resolved until 2021.

More recently, Apple has been found to transmit analytics even when analytics sharing is disabled on iOS, and this data appears to be easily linked to unique iCloud account identifiers despite supposedly being anonymous.

iCloud

The majority of privacy and security concerns with Apple products are related to their cloud services, not their hardware or software. When you use Apple services like iCloud, most of your information is stored on their servers and secured with keys which Apple has access to by default. You can check Apple's documentation for information on which services are end-to-end encrypted. Anything listed as "in transit" or "on server" means it's possible for Apple to access that data without your permission. This level of access has occasionally been abused by law enforcement to get around the fact that your data is otherwise securely encrypted on your device, and of course Apple is vulnerable to data breaches like any other company.

Therefore, if you do use iCloud you should enable Advanced Data Protection. This encrypts nearly all of your iCloud data with keys stored on your devices (end-to-end encryption), rather than Apple's servers, so that your iCloud data is secured in the event of a data breach, and otherwise hidden from Apple.

The encryption used by Advanced Data Protection, while strong, is not quite as robust as the encryption offered by other cloud services, particularly when it comes to iCloud Drive. While we strongly encourage using Advanced Data Protection if you use iCloud, we would also suggest considering finding an alternative to iCloud from a more privacy-focused service provider, although it is unlikely most people would be impacted by these encryption quirks.

You can also protect your data by limiting what you sync to iCloud in the first place. At the top of the Settings app, you'll see your name and profile picture if you are signed in to iCloud. Select that, then iCloud, and turn off the switches for any services you don't want to sync to iCloud. You may see third-party apps listed under Show All if they sync to iCloud, which you can disable here.

iCloud+

A paid iCloud+ subscription (with any iCloud storage plan) comes with some privacy-protecting functionality. While these may provide adequate service for current iCloud customers, we wouldn't recommend purchasing an iCloud+ plan over a VPN and standalone email aliasing service just for these features alone.

Private Relay is a proxy service which relays your Safari traffic through two servers: one owned by Apple and one owned by a third-party provider (including Akamai, Cloudflare, and Fastly). In theory this should prevent any single provider in the chain—including Apple—from having full visibility into which websites you visit while connected. Unlike a full VPN, Private Relay does not protect traffic from your apps outside of Safari.

Hide My Email is Apple's email aliasing service. You can create an email aliases for free when you Sign In With Apple on a website or app, or generate unlimited aliases on demand with a paid iCloud+ plan. Hide My Email has the advantage of using the @icloud.com domain for its aliases, which may be less likely to be blocked compared to other email aliasing services, but does not offer functionality offered by standalone services such as automatic PGP encryption or multiple mailbox support.

Media & Purchases

At the top of the Settings app, you'll see your name and profile picture if you are signed in to an Apple ID. Select that, then select Media & Purchases > View Account.

  • Turn off Personalized Recommendations

Find My

Find My is a service that lets you track your Apple devices and share your location with your friends and family. It also allows you to wipe your device remotely in case it is stolen, preventing a thief from accessing your data. Your Find My location data is E2EE when:

  • Your location is shared with a family member or friend, and you both use iOS 17 or greater.
  • Your device is offline and is located by the Find My Network.

Your location data is not E2EE when your device is online and you use Find My iPhone remotely to locate your device. You will have to make the decision whether these trade-offs are worth the anti-theft benefits of Activation Lock.

At the top of the Settings app, you'll see your name and profile picture if you are signed in to an Apple ID. Select that, then select Find My. Here you can choose whether to enable or disable Find My location features.

Settings

Many other privacy-related settings can be found in the Settings app.

Airplane Mode

Enabling Airplane Mode stops your phone from contacting cell towers. You will still be able to connect to Wi-Fi and Bluetooth, so whenever you are connected to Wi-Fi you can turn this setting on.

Wi-Fi

You can enable hardware address randomization to protect you from tracking across Wi-Fi networks. On the network you are currently connected to, press the :material-information: button:

  • Turn on Private Wi-Fi Address

You also have the option to Limit IP Address Tracking. This is similar to iCloud Private Relay but only affects connections to "known trackers." Because it only affects connections to potentially malicious servers, this setting is probably fine to leave enabled, but if you don't want any traffic to be routed through Apple's servers, you should turn it off.

Bluetooth

Bluetooth should be disabled when you aren't using it as it increases your attack surface. Disabling Bluetooth (or Wi-Fi) via the Control Center only disables it temporarily: you must switch it off in Settings for disabling it to remain effective.

  • Turn off Bluetooth

General

Your iPhone's device name will by default contain your first name, and this will be visible to anyone on networks you connect to. You should change this to something more generic, like "iPhone." Select About > Name and enter the device name you prefer.

It is important to install Software Updates frequently to get the latest security fixes. You can enable Automatic Updates to keep your phone up-to-date without needing to constantly check for updates. Select Software Update > Automatic Updates:

  • Turn on Download iOS Updates
  • Turn on Install iOS Updates
  • Turn on Security Responses & System Files

AirDrop allows you to easily transfer files, but it can allow strangers to send you files you do not want.

  • Select AirDrop > Receiving Off

AirPlay lets you seamlessly stream content from your iPhone to a TV; however, you might not always want this. Select AirPlay & Handoff > Automatically AirPlay to TVs:

  • Select Never or Ask

Background App Refresh allows your apps to refresh their content while you're not using them. This may cause them to make unwanted connections. Turning this off can also save battery life, but it may affect an app's ability to receive updated information, particularly weather and messaging apps.

Select Background App Refresh and switch off any apps you don't want to continue refreshing in the background. If you don't want any apps to refresh in the background, you can select Background App Refresh again and turn it Off.

If you don't want anyone to be able to control your phone with Siri when it is locked, you can turn that off here.

  • Turn off Allow Siri When Locked

Face ID/Touch ID & Passcode

Setting a strong password on your phone is the most important step you can take for physical device security. You'll have to make tradeoffs here between security and convenience: A longer password will be annoying to type in every time, but a shorter password or PIN will be easier to guess. Setting up Face ID or Touch ID along with a strong password can be a good compromise between usability and security.

Select Turn Passcode On or Change Passcode > Passcode Options > Custom Alphanumeric Code. Make sure that you create a secure password.

If you wish to use Face ID or Touch ID, you can go ahead and set it up now. Your phone will use the password you set up earlier as a fallback in case your biometric verification fails. Biometric unlock methods are primarily a convenience, although they do stop surveillance cameras or people over your shoulder from watching you input your passcode.

If you use biometrics, you should know how to turn them off quickly in an emergency. Holding down the side or power button and either volume button until you see the Slide to Power Off slider will disable biometrics, requiring your passcode to unlock. Your passcode will also be required after device restarts.

On some older devices, you may have to press the power button five times to disable biometrics instead, or for devices with Touch ID you may just have to hold down the power button and nothing else. Make sure you try this in advance so you know which method works for your device.

Stolen Device Protection is a new feature in iOS 17.3 which adds additional security intended to protect your personal data if your device is stolen while unlocked. If you use biometrics and the Find My Device feature in your Apple ID settings, we recommend enabling this new protection:

  • Select Turn On Protection

After enabling Stolen Device Protection, certain actions will require biometric authentication without a password fallback (in the event that a shoulder surfer has obtained your PIN), such as using password autofill, accessing payment information, and disabling Lost Mode. It also adds a security delay to certain actions performed away from your home or another "familiar location," such as requiring a 1-hour timer to reset your Apple ID password or sign out of your Apple ID. This delay is intended to give you time to enable Lost Mode and secure your account before a thief can reset your device.

Allow Access When Locked gives you options for what you can allow when your phone is locked. The more of these options you disable, the less someone without your password can do, but the less convenient it will be for you. Pick and choose which of these you don't want someone to have access to if they get their hands on your phone.

  • Turn off Today View and Search
  • Turn off Notification Center
  • Turn off Control Center
  • Turn off Lock Screen Widgets
  • Turn off Siri
  • Turn off Reply with Message
  • Turn off Home Control
  • Turn off Wallet
  • Turn off Return Missed Calls
  • Turn off USB Accessories

iPhones are already resistant to brute-force attacks by making you wait long periods of time after multiple failed attempts; however, there have historically been exploits to get around this. To be extra safe, you can set your phone to wipe itself after 10 failed passcode attempts.

Warning

With this setting enabled, someone could intentionally wipe your phone by entering the wrong password many times. Make sure you have proper backups and only enable this setting if you feel comfortable with it.

  • Turn on Erase Data

Privacy & Security

Location Services allows you to use features like Find My and Maps. If you don't need these features, you can disable Location Services. Alternatively, you can review and pick which apps can use your location here. Select Location Services:

  • Turn off Location Services

A purple arrow will appear next to an app in these settings that has used your location recently, while a gray arrow indicates that your location has been accessed within the last 24 hours. If you decide to leave Location Services on, Apple will use it for System Services by default. You can review and pick which services can use your location here. However, if you don't want to submit location analytics to Apple, which they use to improve Apple Maps, you can disable this here as well. Select System Services:

  • Turn off iPhone Analytics
  • Turn off Routing & Traffic
  • Turn off Improve Maps

You can decide to allow apps to request to track you here. Disabling this disallows all apps from tracking you with your phone's advertising ID. Select Tracking:

  • Turn off Allow Apps to Request to Track

This is disabled by default and cannot be changed for users under 18.

You should turn off Research Sensor & Usage Data if you don't wish to participate in studies. Select Research Sensor & Usage Data:

  • Turn off Sensor & Usage Data Collection

Safety Check allows you to quickly view and revoke certain people and apps that might have permission to access your data. Here you can perform an Emergency Reset, immediately resetting permissions for all people and apps which might have access to device resources. You can also Manage Sharing & Access which allows you to go through and customize who and what has access to your device and account resources.

You should disable analytics if you don't wish to send Apple usage data. Select Analytics & Improvements:

  • Turn off Share iPhone Analytics or Share iPhone & Watch Analytics
  • Turn off Share iCloud Analytics
  • Turn off Improve Fitness+
  • Turn off Improve Safety
  • Turn off Improve Siri & Dictation

Disable Personalized Ads if you don't want targeted ads. Select Apple Advertising:

  • Turn off Personalized Ads

App Privacy Report is a built-in tool that allows you to see which permissions your apps are using. Select App Privacy Report:

  • Select Turn On App Privacy Report

Lockdown Mode is a security setting you can enable to make your phone more resistant to attacks. Be aware that certain apps and features won't work as they do normally.

  • Select Turn On Lockdown Mode

Additional Advice

E2EE Calls

Normal phone calls made with the Phone app through your carrier are not E2EE. Both FaceTime Video and FaceTime Audio calls are E2EE, or you can use another app like Signal.

Avoid Jailbreaking

Jailbreaking an iPhone undermines its security and makes you vulnerable. Running untrusted, third-party software could cause your device to be infected with malware.

Encrypted iMessage

The color of the message bubble in the Messages app indicates whether your messages are E2EE or not. A blue bubble indicates that you're using iMessage with E2EE, while a green bubble indicates the other party is using the outdated SMS and MMS protocols. Currently, the only way to get E2EE in Messages is for both parties to be using iMessage on Apple devices.

If either you or your messaging partner have iCloud Backup enabled without Advanced Data Protection, the encryption key will be stored on Apple's servers, meaning they can access your messages. Additionally, iMessage's key exchange is not as secure as alternative implementations, like Signal (which allows you to view the recipients key and verify by QR code), so it shouldn't be relied on for particularly sensitive communications.

Blacking Out Faces/Information

If you need to hide information in a photo, you can use Apple's built-in tools to do so. Open the photo you want to edit, press edit in the top right corner of the screen, then press the markup symbol at the top right. Press the plus at the bottom right of the screen, then press the rectangle icon. Now, you can place a rectangle anywhere on the image. Make sure to press the shape icon at the bottom left and select the filled-in rectangle. Don't use the highlighter to obfuscate information, because its opacity is not quite 100%.

iOS Betas

Apple always makes beta versions of iOS available early for those that wish to help find and report bugs. We don't recommend installing beta software on your phone. Beta releases are potentially unstable and could have undiscovered security vulnerabilities.

Security Highlights

Before First Unlock

If your threat model includes forensic tools, and you want to minimize the chance of exploits being used to access your phone, you should restart your device frequently. The state after a reboot but before unlocking your device is referred to as "Before First Unlock" (BFU), and when your device is in that state it makes it significantly more difficult for forensic tools to exploit vulnerabilities to access your data. This BFU state allows you to receive notifications for calls, texts, and alarms, but most of the data on your device is still encrypted and inaccessible. This can be impractical, so consider whether these trade-offs make sense for your situation.