In the last post in this series I discussed the Wi-Fi interface settings. Certainly no less important to privacy and security is the cellular interface. This is an iPhone’s primary interface and managing it effectively is extremely important. Fortunately the iOS 10 cellular settings grant granular control to what can use this interface and what cannot. This post will also address the Bluetooth nad Personal Hotspot settings in iOS.
iOS 10 Bluetooth Settings
Settings//Bluetooth or Control Center: Bluetooth presents challenges similar to those presented by Wi-Fi, though to a much lesser degree. Bluetooth can be used to track your location very accurately, though only over short distances from a receiver. Bluetooth traffic can also be intercepted, but the security of Bluetooth has increased greatly over the last few years. Bluetooth should still be turned off when not in use. Bluetooth can also be toggled on or off from the Control Center.
iOS 10 Cellular Settings
Settings//Cellular: Cellular data is one of the primary communications pathways of iPhones and iPads that have cellular data plans. By default many applications and services on your device will want to access and use your cellular data. Allowing all applications and services to use this data has two potential consequences. Most prosaically, this uses the expensive data that you pay for each month. From a security standpoint, access to a communication pathway allows the application to transmit and share data in the background without your knowledge or explicit consent. I recommend that you restrict the ability to use cellular data to only those applications and services that truly need it to function correctly.
Navigate to Settings//Cellular and scroll down to the applications that are displayed. By default, most of the applications you have installed on the device will be permitted to use cellular data. You should disable this for every app that does not require a communication pathway to perform its desired function. This is largely up to your uses of the applications you have, but think critically about each one. For example, I do not allow the App Store to use cellular data. Even though I download apps I can usually wait to do so until I have a Wi-Fi connection because apps are relatively large files and just a few can use a significant amount of data. I disallow photos for other reasons. Because I do not share photos through iCloud or any other service, I disallow cellular data access for Photos.
For some apps it is necessary or desirable for you to allow cellular data. Maps is a good example. Without the ability to use cellular data the Maps app cannot retrieve imagery, plan routes, or search for addresses, except when I am connected to Wi-Fi. This limits my ability to use maps to an intolerable degree, so I allow maps to use cellular data. Mail, phone, and messages likewise have access to cellular data so that I can receive emails, phone calls, and texts.
Wi-Fi Assist: This setting is located at the bottom of the iOS 10 Cellular settings. When enabled it allows your phone to use cellular data to supplement slow or weak Wi-Fi connections. Wi-Fi assist may use a significant portion of your data plan if you are browsing through what you assume is a Wi-Fi connection. Additionally, knowing exactly what interface (cellular or Wi-Fi) your device is using at a given time may be important for your security. Disabling Wi-Fi Assist allows you a degree of certainty that your phone is only using Wi-Fi when you are connected to a Wi-Fi network.
RECOMMENDATION: Make a decision about each application that is requesting access to cellular data. If the app does not need cellular data to perform its desired function, toggle it OFF. Disable Wi-Fi Assist.
iOS 10 Personal Hotspot Settings
The Personal Hotspot function allows you to tether your iOS device to a computer or other device to provide it with an internet connection. Your device can then use your phone and its data connection to access the internet. This allows you to set up a trusted Wi-Fi hotspot anywhere you have a cellular connection. Your personal hotspot is generally much more secure than using a public hotspot that may or may not be properly secured. Personal Hotspot encrypts your connection with WPA2 encryption, and allows to control the hardware and internet connection that your other devices are using.
There are two communication pathways through which the connection can be made with another device: Wi-Fi and Bluetooth or USB Only. If the device to which you wish to tether your iPhone or iPad is USB capable, I strongly recommend selecting the USB Only option. This requires a physical connection to the phone and significantly reduces the chances your traffic will be intercepted. If you choose the Wi-Fi and Bluetooth option, I recommend changing the password somewhat regularly.
Using this option will make the name of your phone visible to anyone with a Wi-Fi capable device; this factor should be considered if your phone’s name is very unique or reveals personal information about you. You can change the name of your device in the General Settings (see this section later in this chapter). Also note that after using the Personal Hotspot in this mode both Wi-Fi and Bluetooth will both be on and must be turned off manually.