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Hi is there an expert out there knowledgeable in the arcane ways windows 10 mobile encrypts the local data on the SD Card?

Long story short my rookie error was not realizing I couldn't re-install the apps and have the previous data accessible to the "new install" of the old app.

To be clear: I had an app installed on the SD card, hard reset the phone and then installed the app again. All previous settings were of course not there..

Doh.

There are some private keys from a bitcoin wallet I'm trying to retrieve... :)

Hail mary pass here but figure it is worth a try to see if anyone knows or can do anything. Thanks

B

  • I'm voting to close this question as off-topic because this is not a jobs board. – Thomas Jan 17 '17 at 21:37
  • Jobs? I'm trying to understand how to decrypt the contents of the/appdata dir.... – Louis Jan 18 '17 at 1:08
  • Why is that not a valid question? – Louis Jan 18 '17 at 1:08
  • "who is willing to work hourly to retrieve some data for me" – Thomas Jan 18 '17 at 1:47
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    @Louis Yeah, edit the post so it's just asking for advice and it'll be fine. – Indrek Jan 18 '17 at 12:46
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I don't know the details of how app data on the SD card is encrypted, but it's a random key that gets wiped when the device is reset. I could show you how to set up a file browser that can pull data out of the SD card's WPSystem folder, but it would only get decrypted correctly on the original, unwiped system.

I'm sorry; that really sucks, I know. You should always keep backups of critical data like that; what if you'd lost your phone?

For what it's worth, some apps will back up data to the cloud and automatically restore it when you re-install the app on a new (or newly-wiped) phone. I wouldn't expect a bitcoin app to do that with the private keys, but I've heard of stranger things. It would need to be the same app and you'd need to be signed into the phone with the same Microsoft Account you were using before.

  • Any idea how strong is the cipher key the SDcard is encrypted with? – Louis Jan 19 '17 at 22:14
  • oh and to be clear: is what you are saying try to re-install the original bitcoin wallet I used on the sd card again? I supposed I can make a copy of the files there first... – Louis Jan 19 '17 at 22:40
  • The encryption is 128-bit symmetric (very likely AES), minimum. Microsoft's internal crypto policies forbid the use of anything weaker on anything except really old code. And yes, I suggest you re-install the bitcoin wallet app. You can install to phone storage if you want to hold out hope for the SD card instead of wiping the old app data yet. – CBHacking Jan 20 '17 at 6:50

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