How to reliably delete digital data

Sasha is a journalist. Information from many sources flows to him. Sasha carefully checks her. In addition to useful materials, shortfalls, provocations, fakes accumulate on its laptop. In addition, Sasha has a lot of drafts. All this must be carefully cleaned and betrayed from time to time. Without the possibility of exhumation.

Nina Evgenievna is an expert auditor. She just completed a great work on the report and handed it to the customer. On the hard drive there are black files. Nina Evgenievna is obliged to delete them, what can be done - an agreement on confidentiality.

Christina works in an office with a database. The client writes and demands that all his personal data collected by the company be destroyed. The client is scandalous, but has the right by law. Christine has to solve this issue.

Bobrov’s birthday was presented with a new cool laptop. Taxed Bobrov decided to do something good with the previous laptop. For example, give it to the orphanage. Bobrov has nothing particularly secret on the computer. However, he is unpleasant at the thought that someone outsiders will look at the family photos of the beaver clan. It is necessary to remove these pictures for good.

In the "basket"

The easiest way is to delete the file from the usual hard drive by pressing the DEL key. The file will fall into the "basket". In fact, the file will move to a special “basket” folder. Such “deleted” data can restore even a beginner. The file will remain in the "basket" until the operating system will record new data over it. If you have a capacious hard drive, a lot of free space, and you do not work to driven horses, in a year you will be surprised to find the files of past days in the “basket”. This method of “removal” is suitable only to hide from the eyes unnecessary.

Past "basket"

The "basket" can be cleaned. And you can press Shift+Del to delete the file immediately, bypassing the "basket". Our auditor Nina Evgenievna will not see her remote report in the “conductor”. But you can still try to restore it using the built-in versions of Windows files and special utilities like Recuva , R-Undelete ( R-Studio ), Disk Drill , PC Inspector File Recovery , etc. (I hope the reader regularly does the backup of data, and he will never need restoration.) Removing “Past the“ basket ”is suitable for not particularly important data, the leak of which does not threaten you or anyone else.

Disk formatting

With “fast” formatting in Windows, part of the files can really be lost forever. The rest can try to restore with different programs. In general, recovery is a probabilistic process. Success depends, for example, on how actively the hard drive was used after formatting. In “full” formatting (starting with Windows Vista), the default disk sectors are overwritten by zeros. This method is long and inconvenient. But you can get rid of information and so, if the disk is not systemic, but not the most important data is to be removed.

Blender, stove, hammer

Do you work in a large rich institution? Are you dealing with secret data? Perhaps your boss will fork out a special destroyer . A device type of shreder with powerful "jaws". A modern industrial destroyer is able to turn a passenger car into a crumb in 10 minutes. (In this video you can see how the discs are destroyed.)

Not kammam? The Internet is full of tips on how to destroy data carriers. They are fried, hollowed with sledgehammers, put them in special composters . If you need to destroy a flash drive or a memory card, you can simply open the housing and break the chips with a hammer. To do this with a hard drive, it will take more effort and time. The destruction of the carrier is permissible once and in a critical situation. But you will not do it every month!

Re -recording

The classic method of software destruction of information is a multiple recording of random data on top of the file. Examples of such programs are Eraser and Bleachbit . Using Eraser, it is convenient to wash individual files from the context menu "Explorer". In the settings, you can indicate how many times the data is rewritten. Eraser has a schedule of erasing function. The program can clean the free (unused) space on the disk. This allows you to get rid of all "pseudo -driven" files at once.

CCleaner boasts the same skill. This conditionally free tool performs many functions and is popular as a “cleaner” of a computer from software garbage.

Bobrov installed CCleaner to clean the free space on the old laptop. And I found in the settings that the number of record cycles can be changed. And how much is needed, "to sure"? For modern hard drives, once is enough. Higher values ​​(up to 35 times, the so -called Gutman method ) - echoes of the time when data could sometimes be restored on special equipment for residual magnetization. Today it is not relevant. In addition, an increase in the number of recording cycles delays the removal process. This is noticeable even on single large files, not to mention cleaning free space. Links to the fact that, they say, three passes are the current standard of the US Department of Defense (DOD) are also outdated. Today, the department deleys secret data by combining different methods, including resorting to the destruction of carriers.

Data deletion on SSD-disks

The above is fair for the usual hard drive (Hard Disk Drive, HHD). The basis of the design of such a disk is rotating plates with an aluminum base and ferromagnetic coating and a block of heads. Christina’s laptop is more hit. It has a solid-state drive (Solid-State Drive, SSD). SSD does not have moving parts. In fact, this is a set of memory chips and controller.

SSDs serve for a long time, but still not as durable as ordinary discs. Therefore, the SSD controller tries to wear the wear of different areas of memory uniform. This is called "leveling of wear." In response to the “request” of the operating system, write data in a specific memory unit the controller can “slip” another memory block, less “hackneyed”. In everyday work, a person will not feel anything. But the program that is trying to rewrite a specific memory block by random data will be deceived. Moreover, SSD manufacturers usually supply their products with a memory capacity of a little more nominal.

"Additional" blocks are also used by a controller for leveling wear. The operating system cannot purposefully “climb” into this area. Therefore, we will not advise Christina to delete files using program programs - no sense.

On the other hand, for SSD in the computer, Data Erasing is normal work with the TRIM function turned on. This function is usually turned on by default. SSD "removes" in the background. This is done to optimize the operation of the disk, the bonus is the inability to restore deleted data. True, only if you have a fresh operating system enough, not some Windows XP, and the disk is not marked in the old FAT file system. Read more about whether your SSD has TRIM and whether it is included in this article . Christina may not worry about additional measures to rub the data. But with a flash drive connected to a USB port or an external hard drive, such a “focus” will not pass.

Encryption

Journalist Sasha uses Veracrypt to protect his files. He learned about this program at security training. Veracrypt allows you to encrypt the whole disc. You can also create an encrypted container and store important information in it. Such a disk (container) will be protected by a password. The password is complex, long, and Sasha stores it in Keepassxc passwords manager. No password - there is no access to files. This means that in order to guarantee to get rid of files, just throw away the password. Sasha just removes him from the password manager. This is a very reliable option. There are simply no ways to restore the password or open the encrypted “safe” without a password knowledge. The password in question, of course, should be reliable . If your data storage opens and closes with a clerical paper clip, getting rid of the paper clip is unlikely to become an obstacle to a persistent attacker.

As you can see, there are different ways of reliable erasing data. I advise you to try encryption (at the same time learn to protect important information). Please, experimenting with different methods of data removal, do not forget to create backup copies.