Our researchers and developers are currently on hiatus to upgrade our data recovery capabilities and success rate when dealing with digital devices such as NAND flash memory chips.
Data recovery for NAND and in some rare cases NOR flash memory is a highly specialized science or process of salvaging and handling the data from damaged, failed, corrupted, or inaccessible digital storage media when it cannot be accessed normally. NAND Flash memory is widely used on many data storage devices such as: USB Flash drive, Compact Flash Card, Secure Digital (SD), miniSD, microSD, Smart Media Card, SDHC Flash Card, Multimedia card(MMC), Memory stick, Memory stick Duo, Memory stick Pro, Memory stick HG, Memory stick Micro, xD-Picture Card, including smartphones, tablets, Solid-state drives, many laptops.
Flash Memory Data Recovery Research and Development
“Flash memory data recovery can easily be represented as assembly of separate encrypted HDD-like images
into an RAID-like structure. This process is tedious. It involves techniques which are very different and involves no cleanroom, no mechanics whatsoever and yet requires advanced skills of file systems. This guide should help you. The rest is up to your ability to get your mind out of the box and resolve the problem efficiently.” – from published version to our new research paper NAND Flash Data Recovery Cookbook.
The image represents a Micro SD card as seen with the X-ray (useful for tracing signals).
Our current research and development is geared towards solid-state drives especially applications where the actual drive is soldered to the motherboard.
NAND Data Recovery
There are two ways to recover data from NAND flash memory:
- Logical Recovery
- Chip-off Recovery
Logical Recovery
Logical Recovery is widely used method which can successfully bring the lost data back only in case when the device is in working order. There are many different software application doing recovery using LBA. Most of them can be easily downloaded from the Internet.
However, in cases when the device has malfunction and it is no longer recognized with the system logical recovery approach is useless and the only way to recover data is the tedious chip-off method.
Chip-off Recovery
Chip-off NAND data recovery include operations such as: Reading Physical Image, Bit error analysis, ECC detection, Physical images extraction (dump reading). These operations are needed just to have dump to memory chip of your device used. From here controller which is in many cases the reason for all the trouble handles: Virtual block sizes, Page structure or (XOR). All together is a part of flash tranlation layer which is responsible of handling I/O operations from and to NAND chip.
In most cases mobile devices uses some sort of flash file system and in which case raw data needs to be interpreted through a specific driver rather than dealing with the flash translation layer.
Some devices have monolithic structure and their NAND chip is integrated or molded into plastic in which case we need to trace signals in order to read NAND content.
Chip-off method has some major challenges: memory chip removal (thermal vs non-thermal), FTL specs, encryption, new technologies, etc.
SSD Recovery
Although SSDs are sharing the same technology with other NAND based digital storage devices their complexity makes chip-off impractical for data recovery purposes therefore other techniques are used.
