I have a Glaxay S4 and I know the password to decrypt the card, and the phone's memory... but the screen is broken and doesn't display anything. Otherwise, the phone is fine.

It's my understanding that one phone cannot decrypt another phone's sd card... so that leads me to wonder if there anyway to remote into the phone and get it to decrypt it's own card without taking any input from the screen (or maybe some other method that I haven't thought of)?

  • Do you have a computer with an SD card reader (and an adapter for microSD cards)? If so, you can use that to decrypt the card. The actual solution depends on what operating system you're using on it - may be a bit easier if you're using Linux. – Arielle Jul 27 '15 at 7:49
  • I'll be more than happy to install a linux VM on my machine, if it works. I'm just not sure how the encryption key is built and whether or not there is a device specific salt. – Troy Knapp Jul 27 '15 at 19:42

Assuming that only the screen is broken, that your device thinks everything is ok and boots up and runs normally you might be able to remotely decrypt the card or access the data, but I think it's a long shot. First, the phone would have to be rooted. Then you would have to connect it to your computer and run a remote access program like Telnet or SSH. Unfortunately, I don't know of any way to do this without enabling or configuring the client device first.

From what I've read, the S4 doesn't use any hardware encryption so you should be able to reproduce the phone inside a VM running on a PC. You would need to obtain the exact ROM your S4 uses, load it into an Android emulator (try Virtual Box) then configure the ROM with your phone's unique (ESN/IMEI, etc.). There's no guarantee this will work as I haven't come across any information on what algorithm the S4 uses for encryption or how it builds the key, but I don't think there's any other way besides fixing the screen.

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  • The phone is encrypted as well, so I have to enter in the password during the boot process, it restarts and then boots up... I'm then prompted to enter in the password again, to unlock it. Because of this... I don't think that telnet or ssh is an option. I can't even get it to boot without interacting with it.I'll try the VM option... it would REALLY surprise me if it didn't use some kind of device specific salt, though. – Troy Knapp Jul 27 '15 at 19:40

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