Having peace of mind on data security goes beyond emptying your recycle bin
SINGAPORE — If you think it is safe to sell your laptop to a secondhand IT shop in Sim Lim Square after deleting your files and emptying them from the recycle bin, think again.
These files are merely placed in a location not visible to you in the laptop’s hard drive. Anyone with basic computer knowledge can easily retrieve them.
A technical expert told Yahoo News Singapore that the deleted files are like books in a library that have been moved from one shelf to another shelf.
Felix Chang, lab manager from Adroit Data Recovery Centre (ADRC), explained, “When you delete a file, the system will mark the file as deleted,...(but) they do nothing with the data. Undelete it and it will appear to you.”
Reformatting a drive also does not make the files disappear as they are still recoverable, he said.
Chang guided this reporter in showing how easy the process of retrieving deleted files is.
This reporter deleted several files from a thumb drive, which was plugged into a laptop. She then downloaded and opened a free data recovery software in the laptop. Within just a few clicks, a list of past deleted files dating to as far back as 2005 was shown and this reporter was able to partially restore an old Powerpoint file and others.
In the case of a hard drive, even if it is partially broken, deleted files can be recovered if the platter and its coating – where data is stored – are intact.
There are several methods to ensure that data in a drive is destroyed and irrecoverable, according to the expert.
One way is to use a data overwriting software to scramble files, Chang advised. Users can download such a software for free and choose an option of one-pass wipe or a higher level.
Another method is to use a powerful magnet to generate electromagnetic waves and destroy the platter in a hard drive.
Using brute force by crushing a device with a hammer may also do the job.
Paying to get your drives ‘shredded’
For those who don’t wish to use these methods, there are companies that can dispose confidential data for a fee.
One such company is Shred-it Singapore, which provides thorough disposal of items such as paper documents, hard drives, SD cards and phones.
When presented with a laptop, for instance, Shred-it can extract its hard drive and use a machine to drill a hole into the drive’s metallic shell.
“If you’re a business and you need to dispose data in a secure and compliant fashion, you’d want to make sure you have a process in place so that that data doesn’t end up in the wrong hands,” the company’s Asia-Pacific sales director Duncan Brown told Yahoo News Singapore in an interview.
Using data overwriting software to destroy files in a drive isn’t ideal, he said.
“There are instances whereby the (data removal) process is not done to the right standard and that data can be retrieved.”
Customers can also opt to have a shredding service conducted at their premises. Shred-it would bring a drilling machine and a shredding machine, which is located in its truck, to do the job on the spot.
A certificate with a unique serial number will then be issued to the customer to ascertain the complete destruction of a device.
Brown said that the physical destruction of a hard drive or thumb drive gave clients a “peace of mind” that their confidential information was securely destroyed.
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