New Study: Data Deletion Methods Are Not All Equal

Written By: Ontrack

Date Published: September 06, 2022

New Study: Data Deletion Methods Are Not All Equal

Not all attempts at data deletion are successful. We recently released a study with our trusted erasure software partner Blancco Technology Group where we purchased 122 pieces of second-hand equipment (mobile devices and drives) randomly selected from Amazon, eBay and Gazelle. On a total of 48 percent of the media purchased, residual data could still be retrieved. The small selection of mobile devices housed thousands of files (emails, call logs, text/SMS/IMs, photo and videos) easily accessed after basic data recovery methods were applied.

One area that really hit home for me was on three-quarters of the drives still containing data, the sellers attempted to delete the data. On the mobile devices with data present, 57 percent of the sellers also tried to wipe out residual data before sending it the new owner. Sellers are making attempts at data deletions, but they are not always 100 percent effective.

Maybe you only use your mobile device for pictures, Facebook and surfing the internet and are thinking “What could they possibly do with that information?” Even the smallest amount of data could be used against you. Photos could be altered and posted on social media. They could use information discovered to blackmail you or worse. On two of the acquired mobile devices, the data our specialists easily restored clearly revealed the identities of the former owners. You can imagine what could happen if that data was used with malicious intent.

Looking at the news over the past two or so years, it is easy to see why we should protect our data. From our study, we have found that ineffective methods were used for data deletion. Almost two thirds of the sellers, who had tried unsuccessfully to erase the data before the sale, used the Quick Format Method (61 percent). A smaller percentage relied on insufficient reformatting (14 percent) or tried a random overwrite of the data where the result was incomplete (11 percent).

The results of the current study clearly show selecting the appropriate data erasure method is challenging. We recommend that all resellers of discarded hardware – whether private or businesses –choose one of the following methods:

  • Full Format
  • Low-level Format
  • Professional Erase Software
  • Cryptographic Erasure: Encrypt the data on the drive

No matter which method you choose – it is extremely important to check the result and verify that all the information on the device or storage medium has been completely deleted before sending it to the new owner.


KLDiscovery Ontrack Canada Co, 155 Gordon Baker Rd Suite 100, North York, M2H 3N7, Canada (see all locations)