Reasons for Disk Data Destruction

release time：2021-04-04

Electronic product destruction, due to the basic principle of storage of magnetic materials and the way of reading and writing data and information, general data destruction such as low-level formatting, data deletion, etc. cannot completely eliminate data information; the potential of computer operating systems and hard disks Operation will result in residual data information. In order to better prevent criminals from using the residual data to repair the original recorded information, which will lead to the risk of security leakage, a different confidentiality level must be used before the hard disk is damaged or sent for repair or donation. Destroy hard disk data information. The key methods of data destruction and the reason why data information cannot be completely destroyed are described in detail below:

2.1 Data information after low-level formatting is repairable

The destruction of electronic products, today’s fashionable low-level formatting, is just a simple process of writing logos. The enabled disks and tracks have undergone transformation, and they are not actual operations on physical tape drives and disks. After the low-level "factory reset", the data information on the hard disk can be repaired, so there are unsafe elements.

2.2 The actual operation of advanced formatting cannot completely delete data information. Advanced formatting is just to create a new upgraded empty document database index for the computer operating system, and mark all the tracks as "not applied", so that the computer operating system feels the computer hard disk There is no document on it. When the customer carries out the actual operation of advanced formatting on the hard disk, first scan each track of the hard disk and ensure that it can be used. Next, load the addressing system software, the root directory of the hard disk website, and the document allocation table. After the actual operation of restoring factory settings, the system software creates a new website root directory on the hard disk, and the information content originally stored on the hard disk becomes impossible to browse. Therefore, the hard disk data after restoring the factory settings can be repaired, which means that Data information is not secure.

2. Three dELETE cannot be erased in actual operation

Because of the consideration of high efficiency and many other aspects of the information content of the hard disk, the deletion instructions applied by the customer, such as DEL, are completed by enabling the WIN32 function. In fact, deleting the system file is only the first item of the file name item of the document. Change the number of bytes to a special symbol "E5H" (or sigma in lowercase letters), make a deletion mark, mark the clusters they occupy in the FAT table as empty clusters, and remove the file directory area from the system files The database index connection between the folder name and the document data information in the data information area only destroys the FAT or FDT table of the document, and the data information area does not change. It is the computer operating system that solves this type of setting during storage. Using software tools to bypass the computer operating system, immediately operate the hard disk, and restore the deleted documents, presenting an opportunity for the leaker, so this type of data erasure method is the most insecure.

2.4 Disclosure of random copies of data and information

According to the scruples about viral infection and content loss, customers often backup data for key data information. Sometimes this kind of backup data computer operating system is fully automated.

The whole process of all copying is very concealed, and it is not easy to leave all marks. If the customer does not carry out the relative solution to the backup data when erasing the data information, it will cause the residual of the "copy" data information. This will give the hard disk information. The maintenance of content and the confidentiality of information have created many unsolvable problems.

2.5 The original internal system of the hard disk makes it impossible to cover some data information

Electronic product destruction

For example, each disk of the old hard disk has the same total number of tracks, but the outer disk is longer than the inner disk, and the secret data may be hidden in the gap between the tracks of the outer disk.

Another example is the system for solving the shortcomings of hard disks. For magnetic storage, the method of projection is generally used to replace damaged disks or tracks. Enter the system software reserved area of the hard disk, replace the old hard disk defect directory, and generally no longer carry out actual operations on the damaged disk or track. Moreover, there are also some mobile phone software or virus programs that can intentionally mark some tracks as bad tracks. If more sensitive information content is stored in the record gap of the hard disk, the bad disk, and the area that is intentionally marked, this information content can still be loaded in a unique way.

The destruction of electronic products is another example of the error correction system. Many storage machines and equipment apply different error correction plans to facilitate data restoration when the equipment is harmed. Therefore, even if some data information is reliably erased, according to the application The built-in error correction capabilities of the storage machinery and equipment are also likely to be repaired.

In addition, for the storage of data information caching or high-speed caching, the computer operating system collects data information in the buffer area before loading the running memory data information into the computer hard disk, and the smallest unit of data information loaded on the hard disk is a track. Therefore, the final part of the document is generally not easy to fill the last track. The computer operating system will arbitrarily obtain the data information called the running memory residue in the buffer area to fill the free area, and this kind of running memory residue data information is being deleted. During the actual operation, it is very likely to stay in the buffer area and not be implemented. Similarly, the unused tracks in the last cluster are preserved intact and the data information originally called hard disk debris. This area called debris is very It may include a lot of more sensitive information that cannot be completely destroyed.

2.6 The magnetic effect of residual current makes it possible to restore data

When electronic products are destroyed, all magnetic media have the problem of residual current magnetic effect. The magnetic media will be permanently magnetized at different levels. Therefore, the information content recorded on the magnetic media will not be cleaned up to a certain level. In addition, because every time it is loaded The magnetic induction intensity in the data information is not completely consistent. This type of inconsistency causes a "level" difference between the new and old data information. The remaining magnetization and "level" differences are likely to be detected by high-precision optical microscope inspection methods. After analysis and calculation, "deep-level data signal restoration" of the original record can restore the previous figure data information.