I am new to Android because I was an iOS user before and the first thing I came across on the way is that with Android it is possible to expand the memory via an SD card.
The disadvantage, however, is that the merged memory encrypts the data, but the data is unusable if it is defective. The other method is not to use the SD card as a shared volume but as a separate data carrier. The problem, however, is that in the event of theft, data such as application documents etc. is read in.
Is it possible in any way to encrypt the data on the external SD card so that the data can still be read by entering the password and on multiple devices.
You couldn't encrypt the SD card on a computer and activate it on the Android device with a password. Or the Android device itself can offer encryption options. For example, there is a virtual volume like macOS introduced with hdiutil to create UDIFs so that the disk image could be read when the password was entered and it worked like a real virtual encrypted disk.
I hope you can roughly understand what I'm getting at, ihow to encrypt the data and to be able to access everyone again when the password is entered, on all devices.