@Clare.
If Bitlocker was installed by default you might be able to obtain the decryption key via the Microsoft account used to log in (that's if one was used).

Hello,

@Clare: There are few issues in this case.

First: Chip is protected by CMD42 extCSD - there is common problems in Samsung chip (due bug close fuse but such operation are implemented in each eMMC starting from v5.0) but also SanDisk chips (as yours one) also got same issue. Basically ,you can protect it on every phone/tablet. In your tablet this can be caused by bug or can be implemented by producer - there was some Lumia phones protected and key was binded with CPU. Only way to access your data are NAND protocol - there are NO other way (in case of SD cards there was possibility to Bruteforce this using SPI but SPI in eMMC/eMCP are blocked).

Second: Once you will read it over NAND you will need to reeasembly image to get FULL logical structure - without this you cannot apply Bitlocker key to decrypt your data.

So if you need more help first post photo of your SanDisk chip here, there are 95% that it can be read by NAND, then get full assembly to get logical structure and then after this apply key to decrypt Bitlocker (you can get this from MS account if Windows was installed with this account)

P.S
In few words: Chip is NOT encrypted - chip is protected by password to not allows reading - need NAND to read it . Data on Chip are encrypted by Bitloader - key are needed to decrypt those or it's possible to decrypt it by Bruteforce (this will cost a lot due power needed to defeat encryption)

_________________
Best regards,
Boguslaw Rzepka,
Multi-COM Ltd., Poland

Thank you for that. I think I am going to send it to Arvika to do the work, as this is now seriously out of my league and they have the expertise and equipment to do it. I can see the Arvika website in English with the shipping instructions, I kept the returned chip in the packaging it came from the phone shop company.

I have sent the chip to Arvika. It's not simple (to me), there has been bad weather and you are probably very busy. I'm just replying here to ask about progress. This is what the page says:

History of status changes:
Contents Date
Visual inspection / repair quote 19-02-05 21:09
Accepted for service 19-01-25 18:37
My orders:
Lp Date of acceptance Order number Status Name
1 2019-01-25 17862
Visual inspection / repair quote eMMC chip

Have you sent me a quote for repair which I have not found so need to respond to?
I am writing here because e-mailing in Polskie is difficult for me and the person whose job is to reply to e-mails may not speak English.
I will wait as required. Thank you.

Clare. You can also PM Arvika through this forum which may be a better option for you.

_________________
HDD, SSD, Flash and RAID Data Recovery
Founder of The Data Recovery Professionals Group

Please use PM or email to: biuro @ odzyskiwanie-danych.com.pl I speak English

_________________
Flash Killer - everyday new resources (pinout, XOR, ECC,config) for flash devices

Thank you ddrecovery I will do that

Michal at Arvika has responded to my PM, I will e-mail Biuro with any enquiries in future. Once ddrecovery came up with something I just did it and didn't refresh the thread, so I didn't see your reply, which is why I went for the PM option.

Michal is very good. You are in good hands.

_________________
HDD, SSD, Flash and RAID Data Recovery
Founder of The Data Recovery Professionals Group

Hi I don't know if this is going to help maybe I am misunderstood or not but if you can mount the image and if it's bitlocker you can make a live Kali linux usb and install dislocker you will need to recover the key from Microsoft. Dislocker is comand line script but there are a few gotos online i dont know if it helps if you want more details just let me know I don't know if it helps but good luck. I have run into bitlocker problems before and it's a pain but gparted in linux will tell you what encryption it is as long as it's full disk image.

There were a couple if issues with this which is why it was referred to Arvika. It seems like the eMMC was locked from a firmware standpoint and as a secondary issue may have also been encrypted with Bitlocker for which the client did not have the recovery key.

_________________
HDD, SSD, Flash and RAID Data Recovery
Founder of The Data Recovery Professionals Group

Sorry for the late reply. ok yea I understand. Thanks for explaining