Many users who are early adopters of iOS 14 will encounter the App requesting a permission named "Local Network" after the upgrade is completed.
iOS 14 new "Local Network" permission reminder
I believe you have a lot of questions about this permission: What is the local network permission? Why should it be restricted? And which applications really need this permission? These three questions will be answered in this article.
What is the local network authority and why should it be restricted?
Local network (LAN)
The local network is also called the local area network, which is the network formed after the device is connected to the router, and the devices can communicate with each other through this network , Allows you to play songs from the wireless speaker on your mobile phone, print documents on a public printer at the company, and play games online with Switch at a friend’s house.
Starting from iOS 13, if an app wants to obtain the name of the Wi-Fi currently connected to, it must obtain location permission. Because by identifying the Wi-Fi name, the application can easily establish a big data network between you and the people around you. But not giving the location permission does not mean that the application cannot track you, because the application can be tracked through devices in the local network.
can identify a specific local area network by MAC address
In the past iOS version, the application can scan the devices in the local network at will, so the application can easily get the local network The names and MAC addresses of all devices. MAC address is an address that confirms the location of network equipment. Each network card has a unique MAC address. In addition, the MAC address is also unique. The equipment manufacturer will allocate MAC according to certain rules, so different LANs are unique. Recognized.
In this way, a specific "fingerprint" is generated through the MAC address and the name of the device, and the user's behavior is continuously tracked across applications and devices, and the user portrait is continuously adjusted.
For example, you bought a new camera from an offline channel, and after taking a photo, use the camera's built-in Wi-Fi to import the photo to your phone. At this time, the application with a certain promotion module initiates a scan on the local area network and recognizes a new device. The promotion module uploads the camera's MAC address to the cloud. After a simple identification and comparison, it is easy to know that the MAC address belongs to camera. In this way, apps with a promotion module will add a label like "camera user" to you in the portrait. When you open a shopping app with the same promotion module next time, you will see a bunch of recommendations and cameras. Related stuff.
When program A exchanges data with the camera, program B can also scan the camera
So in iOS 14, Apple began to make stricter restrictions on local network permissions.
Which apps need local network permission?
So which apps do we need to give local network permissions?
For most applications, they do not need to give local network permissions. Because they have no function and will use the local network, the main purpose of requesting this permission is to track users and push advertisements.
HomeKit, AirDrop, AirPlay, and AirPrint all do not require network permissionsWhen it is API-like, Apple will transmit and exchange data under the premise of protecting privacy.
Smart home apps (non-HomeKit type, such as Mijia, etc.), online streaming media screen-casting apps (such as Spotify, Tencent Video, etc.) will be relatively complicated: permissions need to be granted during pairing, and permissions can be granted selectively during control Permissions.
When pairing smart home and TV, the corresponding App can only be paired if the corresponding device is found locally. Therefore, this process must grant local network permissions. After the pairing is completed, most smart home services will The device records to the cloud.
When it comes to control, because the smart home information is stored in the cloud, the App will first try to submit a request from the local when the user is controlling, and if it cannot be connected, then push the request from the cloud to the device, which can selectively grant permissions .
Simple delay test
Pushing from the local and from the cloud, there is actually no big difference between simple switch commands and delay adjustment commands, so it is completely not to give local network permissions Yes. Only when the network environment is poor, when pushing and playing content, will you feel obvious delay and freeze. So I think that smart home apps or online streaming media push apps only need to be opened for a short period of time during pairing, and there is no need to give local network permissions in daily use.
The last three types of apps must be granted local network permissions. They include:
Using the local network for device discovery
Using the local network for data transmission
Network debugging tools
I don't have many applications that use the local network to discover devices. Most of them are apps related to smart homes. Other applications related to this aspect include: applications that invite friends from the same network to join the game and router management applications.
And there are still many applications that use the local network to transmit data. For example, when you use the local video player nPlayer to play videos in the NAS, you need local network permissions; another example is if you want to use a third party to use the photos in your phone Projecting software to the TV also requires local network permissions; another example is that you often use face-to-face fast upload in TIM, and this function also requires local network permissions to work properly. There are many scenarios for using local network to transmit data. Here I just cite three common examples.
The last one is the network debugging tool that geeks use more, such as HE Network Tools. If you don't give the local network permission, all the test tools related to the local network will fail. But I believe anyone who uses this type of application knows to open this permission.
Fortunately, after the future developer adapts, when requesting local network permissions, you will see which functions of this application require permissions, and help you better judge whether to grant them.
The above is the full text of the detailed explanation of the local network permissions of iOS 14. I hope it can help you.
