The mechanisms for storing, deleting and Data Recovery Tampa FL in solid state drives are a classic “dark forest” in the view of both ordinary users and forensic experts. Unlike traditional magnetic hard drives, the data on which remains in place even after a file is deleted, solid state drives are able to independently start and maintain the process of permanent destruction of information, one has only to apply power to them.
Thus, the procedure for removing a disk image, which is standard during the examination process, leads to the fact that by the time the process is completed, there are no traces of Data Recovery Service in Tampa deleted by the user on the SSD.
Until recently, the only way to access remote blocks was the time-consuming procedure of extracting chips and directly reading information (with subsequent addressing reconstruction). Now, at last, there is a reasonable alternative. Let’s try to understand the mechanisms for storing and deleting information on modern SSDs and try to recover data in deleted blocks.
This article does not describe, but is of particular interest, the vulnerability of the popular BitLocker drive encryption algorithm, which is an integral part of Windows. Instead of software encryption using the CPU, the researchers found , BitLocker can use an SSD controller to encrypt data. Accordingly, low-level access to the SSD allows you to find the data encryption key and decrypt the contents of such a drive.
Unlike magnetic disks, on which data is written more or less sequentially (although traditional drives can also remember the bad block redirection tables and the features of SMR recording), there is no question of any linear recording in SSD drives. The data is divided into blocks that will be written on several chips in parallel mode.
Already at this stage, we have a record that is somewhat similar to writing information to a RAID 0 array (stripe). But even within a single chip, Twitter data is not stored in a linear sequence. This is due to the block forwarding mechanism.
The need to redirect physical blocks initially arose as part of the fight against premature cell wear. As you know, the disadvantage of SSD is a limited number of rewrite cycles. As a rule, manufacturers guarantee the operation of the drive within 1000-1500 rewrite cycles. Due to factors such as an increased write amplification factor, this number can be significantly lower.
Obviously, with standard block addressing, cells that are frequently overwritten would fail fairly quickly, leading to data loss. To combat uneven wear, manufacturers use complex load balancing schemes. The disk controller knows how many times each physical cell has been written to. In order to write to the cells with the least wear, the controller replaces the addresses of the cells: writing a data block at some “physical” address can actually be done in any cell on any of several memory chips.
