I'm looking for a solution that would allow to encrypt external microSD card with the following conditions:
- external microSD card is not merged with the internal storage;
- encrypted external microSD is mounted upon booting automatically;
- content of an encrypted microSD card can be viewed in another Android device and Windows/Linux PC if the smartphone where this card has been used was physically destroyed beyond repair.
The motivation behind these criteria stems from my workflow on a desktop computers. All of them have both system and storage drives fully encrypted with VeraCrypt. I set them up in a way that I enter a password upon booting once, and all the favorite volumes are automatically mounted and I boot into fully functioning system. On the other hand, if for some reason I cannot boot anymore (e.g. missing or corrupted system drive), I can take off the encrypted data drive, plug it into any other machine running Windows/Linux/MacOS with installed VeraCrypt and decrypt my files in no time.
However, I cannot achieve the same with the default encryption offered by Android. To encrypt the SD card, one must merge it with the internal memory, and if the device fails to start, there is no easy way to recover/decrypt my data from the external card.
I searched Google Play and couldn't find any third-party app similar to VeraCrypt.
There are related topics, but I couldn't find an answer in any of these either:
- Decrypting Encrypted Micro SD Card without phone
- How to decrypt Adopted Storage?
- How to decrypt a microSD card after a factory reset of the device used to encrypt it?
I'm using a rooted Moto G5s running Android 8.1, but a vendor-independent answer would be more preferable.