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encrypt SD card

Added by E D over 2 years ago

hello,

On my S3 I9300 I put an external SD card, let replicant format it.

I heard it is possible to format it to ext4 in order to better manage rwx right.

Nevertheless, if I create an ext4 filesystem on my SD card and want to transfer previous data
on it, which owner ? which group to use ? Does it depend on the apps which needs the data ?

furthermore, to increase security, is it possible to encrypt the SD card, like on ubuntu with cryptsetup LUKS tool ?

Thanks for your attention

Best regards


Replies (10)

RE: encrypt SD card - Added by E D over 2 years ago

Answeering to myself, I searched around, it appears that encryption can be achieved with "vold" program
which is somewhat equivalent to "cryptsetup", i.e. it both use dm-crypt, as far as I understood.

Has anyone tried to encrypt its external SD card like this ?

Best Regards

RE: encrypt SD card - Added by E D over 2 years ago

Any hints about how encrypt the external SD card ?

RE: encrypt SD card - Added by tristan k over 2 years ago

I also searched for a solution and the only one I came up with is to use a proprietary app from google play called "EDS". It supports mounting LUKS & TrueCrypt Volumes. Have a look at https://play.google.com/store/apps/details?id=com.sovworks.eds.android&hl=de. I would be happy to see a "native" solution.

RE: encrypt SD card - Added by Paul Kocialkowski over 2 years ago

I'm not sure whether the system also encrypts the external SD card when encrypting the storage. One would have to try and see.
If it already has an ext4 partition, it will most likely keep it (it's very usual to use ext4 for internal storage now, so I doubt it'll be a problem).

RE: encrypt SD card - Added by tristan k over 2 years ago

It does not encrypt the external sd card. I tried that. It seems there is no easy way in achieving that.

RE: encrypt SD card - Added by E D over 2 years ago

Hello,

There is an on going project to port LUKS on android at guardianproject : https://guardianproject.info/code/luks/

RE: encrypt SD card - Added by My Self over 2 years ago

As a workaround, until the solution (for whole disk encryption on external SD card problem) is here, you could use apps to encrypt your files like:

RE: encrypt SD card - Added by tristan k over 2 years ago

This are all great applications but they dont allow full disk encryption. I also started a thread at http://android.stackexchange.com/questions/108376/how-to-encrypt-an-external-sd-card-natively

RE: encrypt SD card - Added by My Self over 2 years ago

Probably someone screws up one's courage to backport the native ext4-encryption, (which was introduced with Linux-Kernel 4.1

and which should be used in future Android versions), to older Kernel versions.

RE: encrypt SD card - Added by Daniel Kulesz about 2 years ago

Actually, my preferred way to actually enable SD card encryption and solve many other problems (like running out of internal storage) is by moving ALL data, including the "internal" data to encrypted sdcard by following this tutorial:

http://forum.xda-developers.com/android/software/internal-external-data-encrypted-t2996421

Of course, this works best with devices having a "real" sdcard, and even with a rather fast sdcard the system feels a little slower than when running off internal flash. But since you can buy a UHS-I 32GB Sandisk card for less than 10 euros nowadays, the disadvantages are rather negligible in the light of its advantages.

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