How to completely destroy the hard disk data: data recovery experts tell you

On December 2, a shooting at Lake Secom was reported, killing 14 people and injuring 22 others. The FBI carried out a search of the lake after it learned that the suspect’s discarded laptop in the lake might contain email and other evidence related to the case. Data forensics experts said that if the hard drive just soaked in water, data recovery is actually not difficult. In fact, there is a more efficient way to destroy a hard drive.

Destroy the hard disk
Destroy the hard disk

The data on the hard disk is stored in 0 and 1 on a platter made of aluminum block, ceramic or glass and looks like a CD. The center of the disk is a spindle that controls rotation. The head uses current to read and write data. The actuators and other electronics control the entire operation.

Water may short-circuit the electronics of the hard disk, but the data is not lost, whether the disk is wet or dry. Russell Chozick, vice president at Flashback Data, explains: “Forensic experts are able to recover data very easily as long as the disks do not dry out, as it leaves some hard-to-clean traces.”

Russell Chozick said modern SSDs and flash memories are actually more likely to “drown,” most of which come with on-board encryption, meaning that the drive’s circuit board must decode anything stored on the memory chips. However, SSDs currently account for only one-third of the PC hard drive market, so traditional rotary drives remain the areas of greatest concern.

So, what is more effective than water damage? Some professional IT people tell us that the magnets close to the hard disk may not be effective in destroying the data. Gleb Budman, chief executive and co-founder of Backblaze, a cloud-storage company, said: “The first thing to do is to fix the steel case in the hard drive and then place a strong magnet close to the disc so that it can effectively disrupt the data. It is the safest way to break the disc. ”

In fact, we can easily open a hard drive in a few minutes with a screwdriver and a hammer, and using brute force is the best way to destroy it in a short time. Russell Chozick said: “The laptop hard drive usually uses a glass disk, if you hit hard, the glass will be crushed, and no one can recover.” Of course, in some cases, to restore the glass disc The data is not impossible, but it is a lengthy process, and the cost of recovery is prohibitively expensive.

Desktop hard drives are mostly aluminum disk, we need to spend more effort to destroy the data. For example, a large scratch prevents the driver from being initialized and can hinder traditional data recovery efforts. Of course, the aluminum disc or large cracks on the same effect.

However, Gleb Budman said advanced labs are perfectly capable of reading data from less than complete disks, and they do not even need hard disk rotation, and experts can recover enough data in the disk to read 0s and 1s take.

In addition, the heat generated by drilling the disk can easily lead to large-scale destruction. This may distort the disc itself and result in subtle changes in all the discs. To completely invalidate the data in the hard disk, in fact, do not need to change too much, a little bit is enough.

If you think there are several ways above are not enough insurance, you can consider using acid to completely peel off all the information on the disc. Of course, we can also erase the data on the hard drive in a less aggressive way. For example, on Windows and Mac OS X, we have a similar erasing tool that can overwrite existing ones with random zeros and ones data. Gleb Budman suggested that the new hard drive need to be wiped twice, the best old hard drive to wipe seven times, otherwise, some advanced laboratories can still find “clues” in the covered data.