Cross-platform compatible encryption of SD-card for Android

How would I go about encrypting my brand new 256GB SD-card, which is meant for my Android phone, considering the following:

• Card should be usable across multiple Android devices, and other platforms (Linux..). As a consequence, native Android SD-card encryption is not a solution as the contents are not readable on other platforms, nor recoverable if the phone fails or needs a reset.


• Use case is protecting data, mostly pictures, from phone thief/finder, not from a gvt agency or police. My understanding is that most encryption methods are broken on Android for these purposes as the keys are often accessible from memory. In that sense, the phone is considered trusted once unlocked, so encryption should be transparent so that files are accessible via standard phone apps (i.e. pictures show in Gallery).

Ideas:

• Full disk encryption methods such as Luks. I found this program : EDS which apparently can mount Luks volume if the phone is rooted. I have no idea how efficient this is performance-wise, or if it is safe for the card.


• Commercial programs using their own file-based encryption but available on multiple platforms such as Boxcryptor, or Cryptomator. Their purpose is originally to encrypt files before storing them in the cloud. It doesn't seem that I can access files using regular apps using this solution.


• Changing my phone to one on which I can install UbPorts :)


• Using Termux and rooting the phone to mount a gocryptfs or other encrypted file system


• Using Android default sd card encryption (FDE/FBE), dumping memory to get access to the encryption key and using that from Linux to access files


• Other welcome idea !

I cannot find any info about this use case which seems very strange to me..

Thank you very much for any input !

keyboard - How can I set the locale and language?

How can I set the keyboard and language in Android, and how can I add more languages to the device?

TCP/IP tethering over Bluetooth

I have a Samsung Galaxy Player 5.0 and I would like to browse the web over a bluetooth connection to my computer. I can connect to the computer but the browser doesn't have internet connectivity even though the computer does. Also, the Bluetooth standards indicate that this is supported.

Anyone ever have this issue?

Why does a factory reset keep the operating system updated?

This question already has answers here:

Closed 3 years ago.

I recently did a factory reset to my phone and to my surprise, the operating system remained to the last updated version (6.0.0) and not the version I had when I bought the phone (5.0.0).

Why does this happen? Doesn't a factory reset reset the operating system too?

Answer

System updates overwrite /system. Factory reset wipes /data and /cache but doesn't touch /system. Simple as that.

comparing signatures of apks

I have two .apk files that are supposed to be different versions of the same app. What is the best way to check if they where both signed with the same key?

(I want to make sure no mistakes where done and the newer version would be treated as an update of the same app).

wi fi - Connect android phones through adhoc wifi network

I want to connect my android phones (two Galaxy s2 and two nexus1 phones) in adhoc mode through wifi connection. Something like peer to peer network so that I can transfer messages with mobiles in my adhoc through wi-fi connection.

Does android support creating an adhoc connection?

Answer

It might be possible with an app, but it's not built in. Can't you create an ad-hoc network on a computer, then connect the phones?

rom flashing - Can I install a ROM made for a different device?

I own a MicroMax A100. I want to install the latest version of a different ROM (Samsung or Nexus).

Is it possible? If so, can you tell me how?

If not, can I install a ROM made for a different device, but from the same manufacturer? For example, could I install a ROM for the MicroMax A110, which is the successor of A100?

Answer

Short answer:

You can only install ROMs compatible with your device

Longer version

Different Android devices use different hardware, which requires special drivers (e.g. the camera). Those drivers are sometimes/often proprietary (take e.g. Sony, which almost made it into the AOSP project -- but had difficulties due to those proprietary parts and thus had to back-out again: AOSP only allows for non-proprietary, Open Source code, like its name suggests: Android Open Source Project). Installing an incompatible ROM, in the best case, makes components of your device unavailable (they are simply not working). In the worst case, you might "brick" it (it won't even start up).

You might want to check the question Where can I find stock or custom ROMs for my Android device? to find ROMs compatible with your device. Most times, there are several choices available to meet the user's requirements: Less "bloatware" but more performance, more fancy stuff, custom enhancements... So you still can make your pick.

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