You may not have used them, but your phone and computer have several options for quickly downloading files between devices without Wi-Fi or the Internet in general. The idea is that users can quickly transfer data from one device to another or share files with family and friends in a convenient way.
Like many other tools, however, the ease of use of these systems also means that they are open to abuse - and you don't really want random photos sent to you by strangers on the subway. See how you can configure these sharing features so you can use them and stay protected.
iOS / iPadOS
The favorite device sharing protocol on an Apple device is called AirDrop and you will find it installed on software running on your iPhone or iPad: It's a very easy way to send files between Apple devices.
To check who can and can't send you files via AirDrop, go to Settings, then select General and AirDrop. You have three options here: Receiving Off (no one will be able to send you files), Contacts Only (only the people mentioned in your contacts can send you files) and Everyone (anyone can send you files, a setting that will not we recommended).
You can find the same three options in the Control Center by long pressing the panel with airplane mode, Wi-Fi, Bluetooth and mobile options. A larger box will appear and you can then press AirDrop to make your selection.
It is worth noting that even if you leave access open to anyone, you will still have to accept the files sent via a pop-up dialog. However, this is a risk that is probably not worth taking in case you accidentally accept something you do not want.
AirDrop is actually based on Bluetooth, which can be used as the most primitive way to send and receive files. If you want to turn off both file transfer methods at the same time, switch to Bluetooth in Settings and turn off toggle.
You can not restrict Bluetooth connections as you would with AirDrop: Your phone or tablet is either visible or not. However, if another device tries to connect to yours (possibly sending files), you will see a pairing confirmation dialog box that you can discard to block the link.
Android has released several of its own AirDrop-style approaches in recent years, but the latest one is called Nearby Share. It is a file sharing system from Android to Android, although it is not available on all devices.
If you have Nearby Share, you can find it by opening Settings and then selecting Google and Device connections. From this screen, tap Nearby Share to configure how the feature works: If you do not want to use it at all, you can turn it off completely using the toggle at the top.
Assuming you want to use Nearby Share, you can select Device visibility to select one of three options: All contacts (anyone in your contact list can send you files), Some contacts (only the contacts you specify in a list can send you files) and Hidden (no one can send you files).
The above three settings are accompanied by warnings. No matter what setting you use, anyone will be able to send you files if they turn on Nearby Share and you turn on Nearby Share too - this will appear as a tap to make the notification visible on your phone. If you ignore this alert, no one can see you.
Even if you decide to become visible to anyone close to you, any attempt to transfer files will require another confirmation dialog box. This also applies to files sent by approved contacts, so there is at least one and sometimes two pop-up windows to go through before you find yourself receiving a file from someone else.
As with the iPhone, Bluetooth is another option for sharing files on Android, but you'll need to accept a pairing request and a file transfer prompt before sending data. You can not control it in as much detail as Nearby Share, but you can enable or disable Bluetooth via Connected devices and then Connection preferences in Settings.
The options for macOS are quite similar to those for iOS and iPadOS: AirDrop is here and can be customized according to your needs. Open a window in the Finder and you'll see the AirDrop link in the navigation pane on the left - click on it to see AirDrop transfers and settings.
On the AirDrop tab, you can click Allow me to be discovered by to select from No One (contacts can see your Mac), Contacts Only (contacts can only see your Mac) and Everyone ( anyone using AirDrop can see your Mac). As with mobile devices, no files can be sent if your computer is not visible. If your computer is visible, you must approve any file transfer attempts.
Bluetooth is another option for sharing files on a Mac. Open the Apple menu, select System Preferences, and then select Bluetooth to turn it on or off. As with phones, in order for someone to send you a file, you must have Bluetooth turned on and accept the pairing request and accept the file transfer.
Windows has its own file-sharing protocol called PC Nearby Sharing (almost the same as the selected Android name). It can only be used between Windows computers, but it is a convenient way to send files. You will find it in Settings in the System and Shared experiences section.
In the Nearby Sharing section, you'll see a toggle switch to turn the feature on or off, and the drop-down menu below offers two options: Everyone nearby and My devices only. You may want to keep the last option, unless you know someone wants to share something with you, but even if you choose the first one, login requests will have to be approved by you.
As with all other devices, the Bluetooth is also here. From Settings, click Devices and then Bluetooth & other devices to turn it on or off.
Source of information: wired.com