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sallyc1
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Message 1 of 63

SD card encryption issue?

I'm curious if anyone can help with this.  According to this Motorola FAQ about their Android encryption, "When SD card encryption is enabled, all new files added to the removable memory will be encrypted. Files stored on the card will not be readable via another phone or card reader connected to PC. User can transfer files from encrypted SD card to PC using embedded Phone Portal application."  


So what happens if a user encrypts their data and their phone dies?  They will not have the opportunity to transfer it to a PC and the replacement phone will have a different ESN.  Is their data recoverable via any other mechanism or is it lost forever?

androidcore
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Message 2 of 63

Re: SD card encryption issue?

the link states that it uses a AES 256 algorithm to encrypt... 


 


so... that tells me any Encypter that can use AES 256 can also decrypt the files. Many many many many AES 256 decrytion tools are available (simple Google Search "AES 256 decrytion tools").


 


so, in the event the phone does die (for whatever reason/physical damage/water damage/etc)... and a Verizon Store or Motorola Repair cannot decrypt your SD card, then buy decrypter or your computer/laptop (along with a USB/SD Card adaptor for the microSD card)... or download one of the many freeware decrytors online...


 


hope this helps.. 

sallyc1
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Message 3 of 63

Re: SD card encryption issue?


androidcore said:

the link states that it uses a AES 256 algorithm to encrypt... 


 


so... that tells me any Encypter that can use AES 256 can also decrypt the files. Many many many many AES 256 decrytion tools are available (simple Google Search "AES 256 decrytion tools").


 


so, in the event the phone does die (for whatever reason/physical damage/water damage/etc)... and a Verizon Store or Motorola Repair cannot decrypt your SD card, then buy decrypter or your computer/laptop (along with a USB/SD Card adaptor for the microSD card)... or download one of the many freeware decrytors online...


 


hope this helps.. 





 I wish it were that simple.   It's not just the AES 256 algorithm, but the fact that the the encryption defaults to a phone-specific key (MEID/IMEI/ESN), for the AES 256 data encryption ("the card will not be readable via another phone" and "Encryption keys are auto-generated by the key store on the device and are only stored on the device.") means that it's not enough to have just any AES 256 encrypter.


This has come up for me trying to help a user on another forum who had pictures & videos of her 2-3 year old on an SD card when her phone died.  So far we've not been able to come up with any way to recover them, although we've learned alot about Motorola's encryption.


I was hoping by posting here that either someone from Motorola knew of some way around this.  Especially realizing that people use their phones for corporate data (such as financial & healthcare sectors) it seems to me rather difficult to believe that one bad drop/splash/oops could mean the irretrievable loss of valuable data.

Moto Sr Moderator
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Message 4 of 63

Re: SD card encryption issue?

I know how difficult it is to lose data, but...isn't that what data backup is all about?  Isn't one bad drop/splash/oops enough to kill the data on your laptop or desktop?  Whether business or personal, our files hold valuable information, making it all the more important to incorporate some kind of backup plan into our routines.  I guarantee that there's a calamity bad enough to breach the safeguards of any legitimately ruggedized device, so certainly, our phones are no different.


I don't mean to preach about locking the barn door after the horse has been stolen, but the only good that can come of a story like this is that those of us who aren't backing up our data might get jolted into making it happen. 


Does the phone power up at all?  If it does, is there any chance it could be cloned? (even bad things have an occasional good use)

sallyc1
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Message 5 of 63

Re: SD card encryption issue?


crystallet said:

I know how difficult it is to lose data, but...isn't that what data backup is all about?  Isn't one bad drop/splash/oops enough to kill the data on your laptop or desktop?  Whether business or personal, our files hold valuable information, making it all the more important to incorporate some kind of backup plan into our routines.  I guarantee that there's a calamity bad enough to breach the safeguards of any legitimately ruggedized device, so certainly, our phones are no different.


I don't mean to preach about locking the barn door after the horse has been stolen, but the only good that can come of a story like this is that those of us who aren't backing up our data might get jolted into making it happen. 


Does the phone power up at all?  If it does, is there any chance it could be cloned? (even bad things have an occasional good use)



 This isn't about data backup - it's about the ability to decrypt that data if the decryption key is tied to the device.  Even if the data is backed up, you won't be able to unlock it without the key and it appears the only key is stored on the device.  If I backup my laptop and it dies, I can retrieve the data using my backup.  But in this case, because the encryption is tied to the ESN, there is no way to view/restore the data.


There is no way to backup or clone the key as far as I can find. If the device dies - one drop/spill/oops - you're data is gone.  Unless someone here can tell me another way - which I'd love to hear because this seems to me a flawed system.

Moto Sr Moderator
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Message 6 of 63

Re: SD card encryption issue?

I am certainly no expert in this area, but I've done some poking around that suggests that there is PC software out there that might be able to crack the encryption. I also found some info that suggests the data might be recoverable depending on how it was encrypted...it's all over my head.


I meant clone the phone entirely, to fool the card into thinking it was right where it belonged, but I don't even know if that can be done.


It's a ridiculous process at best, but if the phone must be encrypted, then encryption would have to be turned off before new files were stored, backed up somewhere else in unencrypted format, and then turn encryption back on for the phone, which would encrypt the files for safety.

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Message 7 of 63

Re: SD card encryption issue?


sallyc said:

 I wish it were that simple.   It's not just the AES 256 algorithm, but the fact that the the encryption defaults to a phone-specific key (MEID/IMEI/ESN), for the AES 256 data encryption ("the card will not be readable via another phone" and "Encryption keys are auto-generated by the key store on the device and are only stored on the device.") means that it's not enough to have just any AES 256 encrypter.


This has come up for me trying to help a user on another forum who had pictures & videos of her 2-3 year old on an SD card when her phone died.  So far we've not been able to come up with any way to recover them, although we've learned alot about Motorola's encryption.


I was hoping by posting here that either someone from Motorola knew of some way around this.  Especially realizing that people use their phones for corporate data (such as financial & healthcare sectors) it seems to me rather difficult to believe that one bad drop/splash/oops could mean the irretrievable loss of valuable data.



I looked into this last Fall and my thinking is pretty much in line with yours.


The key is auto-generated by the device and only stored on the device.  Additionally, if you FDR the device, you will lose the current key, and a new one would be generated.  Again, leaving you without access to your data.


I think that the idea is that items are encrypted for transport (on your handheld device) or think of it as the data is more accessible while we go about our business in public than it would be on our home computers.  I also think that we are supposed to back up the data to our private storage (like your own computer) and in the process of data migration from the device to the computer your data will be unencrypted.


I know this doesn't help, but I am just affirming your conceptual understanding of the encryption for Moto devices.


 


FYI:  Most of what I understand about this topic was learned from this post by @D.Harris


Source:  https://forums.motorola.com/posts/6e41d89eed







Greetings,


I can provide some information---but not a lot.


First, let me state up front that I have not yet used this feature. Why? Because I've had to do more than one factory data reset and I anticipate doing more before the current GB 2.3.3 mess is over. Using encryption complicates a factory data reset and adds more work to the process.


Second, looking to the future, if I keep my Droid X phones and continue to use Motorola's version of GB 2.3 (both are up in the air right now) then I plan to make good use of the encryption option in the future. It appears to be an excellent feature.


Our understanding of the new encryption feature comes directly from Motorola. There are two places where this information is provided and they are both in our Droid X phones. I'll quote them in dark red:


Source 1: The caption under Android menu > Settings > Location & security > Data encryption


"Protect the data on your phone or memory card. Requires screen lock."


We can conclude the following from the above quote:


  1. "Data" is what is encrypted. It is safe to assume that this includes all user data (such as contacts and calendar events stored on our phones). What we don't know is if this also includes system data (the settings and data cache of Android) and app data (such as our app settings and our Browser's cache).

  2. Since the statement says "on your phone or memory card" we can also conclude that data is encrypted either in the internal memory of our phones or on our micro SD memory cards (or both). It seems that only data is encrypted in our phone's internal memory just like the title of this feature suggests ("Data encryption"). However, it also appears from Source 2 below that the entire micro SD memory card is encrypted. Therefore, if we have any apps stored on our memory cards, they will also be encrypted. This shouldn't cause a problem for our phones---they will simply decrypt them as they read our cards. I believe it will work the same way when we attach a file to a text or email message that resides on our memory card---our phones will automatically decrypt the file and the attachment would not be encrypted (but someone needs to test and confirm this).

  3. The "Data encryption" feature is only available when the "Screen lock" option is turned on. It is safe to say that the pattern, PIN or password that we choose for the Screen lock will also be used to generate the key for the encryption. That way we only need to remember one pattern, PIN or password. If the Screen lock feature is turned off, then we cannot use the Data encryption feature.


Source 2: The text displayed during a factory data reset (Android menu > Settings > Privacy > Factory Data Reset).


"Encrypted files on your memory cards will become unreadable. It is advisable to connect your device to a PC and copy the files you would like to keep from each encrypted card before resetting the device."


"Encrypted files created on this phone and saved to the memory cards will become unreadable."


We can conclude the following from the above quote:


  1. A factory data reset will destroy the encryption key, making any encrypted data or files unreadable both in the phone's internal memory and a micro SD memory card. Therefore, we must connect our phones to a computer and copy the encrypted files to an unencrypted location on our computers' hard drive for safekeeping during the factory data reset.

  2. In order to copy decrypted files to a computer, the card must remain in the phone so the phone can decrypt them. In this way, the copies of the files that were moved to our computer would no longer be encrypted. This means we will have to connect our phones to the computer via either USB or bluetooth. The card cannot be removed from the phone and inserted into a third-party reader. If that were done, the card would be unreadable.

  3. Even if we choose to use an identical pattern, PIN or password for the Screen lock after a factory data reset, a unique encryption key will be created, making files encrypted under the earlier key unreadable (even though the same pattern, PIN or password were used). If a card became unreadable because its encryption key were lost, the card would need to be reformatted before it could be used again (reformatting it will effectively erase it).


As you can see, this still leaves a lot of unanswered questions. How strong is the encryption? Will the encryption affect performance? What exactly happens if I turn off Data encryption? Will all the formerly encrypted files be immediately decrypted?


Kind regards, D.Harris




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sallyc1
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Message 8 of 63

Re: SD card encryption issue?

Thanks, eaccents.  I appreciate your input and the link. Very informative and, unfortunately, confirming what I have been learning about the risks of data encryption.


I don't think most people who use the encryption are aware of how vulnerable they are to irretrievable data loss.  Indeed, they choose it to provide security. It does not seem well documented to me anywhere that if your phone should fail (not an extremely uncommon event) you will lose all your data.  


Perhaps there is a warning about losing data when doing a factory reset, but by the time someone gets to the point of doing a reset their phone may already not be fully functional, stable or accessible and, even more importantly, many folks  will not even be given the chance to do a reset - their phone just dies due to the unexpected drop/spill/oops of life.  Even if they have the data on an external SD card, thinking it's less vulnerable to "sudden phone death" that way, it will still be lost.


I don't' consider generating a new key every time the phone is reset, and having no way to back up that key to use with another AES 256 program, a feature.  I consider it a bug.  There should be a way to back up your key so that if your phone dies or you need to reset it, you can still access your data. And if the intent of encryption is only to make data 'secure' for short term transport - with the risk that if your phone unexpectedly dies you just lost everything - I think that should be made clear in the documentation and during the set up process.


I would bet most everyone who uses encryption on their phone has no idea of these issues or the risks they are taking.  

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Message 9 of 63

Re: SD card encryption issue?

Let this very unfortunate incident be a warning to everyone who decides to use encryption: under the current encryption scheme, if you want to ensure the longevity of your files, the only way to do it is to copy them to a PC.  Otherwise, the only copy you have will be lost if the phone should fail.   I agree with eaccents' assessment of the scheme: that it's designed to be as secure as possible while we transport sensitive data on our phones. 


The horrendous missing link is the lack of information prior to encrypting.  If a great big warning came up as soon as you reached the encryption menu, you would at least have the opportunity to give yourself a safety net by preserving unencrypted versions of the files.  I agree that providing that information at the point the phone requires an FDR is way too late, and the lack of information in the user manual is ridiculous.  I can understand why making information publc on how to decrypt the data would be counterproductive, but there has to be some way to warn legitimate users in advance.

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Message 10 of 63

Re: SD card encryption issue?


crystallet said:

Let this very unfortunate incident be a warning to everyone who decides to use encryption: under the current encryption scheme, if you want to ensure the longevity of your files, the only way to do it is to copy them to a PC.  Otherwise, the only copy you have will be lost if the phone should fail.   I agree with eaccents' assessment of the scheme: that it's designed to be as secure as possible while we transport sensitive data on our phones. 


The horrendous missing link is the lack of information prior to encrypting.  If a great big warning came up as soon as you reached the encryption menu, you would at least have the opportunity to give yourself a safety net by preserving unencrypted versions of the files.  I agree that providing that information at the point the phone requires an FDR is way too late, and the lack of information in the user manual is ridiculous.  I can understand why making information publc on how to decrypt the data would be counterproductive, but there has to be some way to warn legitimate users in advance.



I agree as well.  There should be better documentation on the encryption function so that users can make informed decisions about how to manage their data safely.  


I will try to flag this thread for some more attention from those that do the documentation for our devices.

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