At DriveSavers, we often receive requests for data recovery from grieving family members who don’t know the passcode to their loved one’s device.
Is Your Data Ever Really Gone?
Right now, the world’s datasphere contains more than 18 zettabytes of information. It’s hard to even comprehend the sheer volume of data existing today. And the shocking part is that this data continues to grow by leaps and bounds… with little sign of slowing down!
Every second, 2.4 billion emails are sent around the world. Every minute, 300 hours of video content is added to YouTube. Around the world, people spend their time watching 5 billion videos on the video streaming giant daily. What’s more, 95 million photos and videos are added to Instagram every day, adding to the 40 billion-plus photos and videos already calling Instagram home.
These statistics are mind-blowing, especially considering they barely touch on data created by our obsession with taking pictures with our cell phones, enterprise data generation and everyday computing. The bottom line: there’s a lot of data out there, we’re creating more every day. And our pace of creation will likely accelerate as our lives become even more reliant on technology.
With so much data being created and stored, you’ve got to wonder, can the information ever, really be erased? Is permanent data deletion possible?
This is a complicated question. Over the years, the tech industry has taken a number of positions on this issue, some more accurate than others. The short answer is yes, data can be permanently deleted, but you have to know how.
The Gutmann Theory
In 1996, a computer scientist by the name of Peter Gutmann presented a paper on permanent data deletion related to cybersecurity. He believed magnetic force microscopy (MFM) could be used to recover previously deleted data.
MFM is a means to read previously overwritten, or deleted data, by using an extremely sensitive magnetic force microscope to physically examine the overwritten data, put the old bits back together and regain the information. Gutmann believed you would need to overwrite at least 35 times to permanently delete the data.
Several companies and organizations signed onto this theory right away, employing multi-pass data deletion practices as a security measure to permanently delete data. Even the United States Department of Defense is rumored to have once used this method to erase hard drives!
Whether or not this method was ever actually effective is a debate for computer scientists. For modern drives, data that has been overwritten is generally unrecoverable. And, if you’re using a solid-state drive, deleted files are removed immediately to speed up your drive’s performance.
How hard drives really work
In reality, when a hard drive writes data to a disk, it’s safely stored away until you need the information. The hard drive keeps a record of where each piece of your data is located on a file table or file system. When you want to look at a file, the hard drive consults the file table to identify the location of the data and quickly retrieves the information.
When you’re looking for how to wipe a hard drive, keep in mind the hard drive usually doesn’t delete the actual data. Instead, references to the deleted data are removed from the file table so when you want to pull up a file, the deleted file doesn’t come up in search results.
So can you really erase hard drive data permanently? The actual data often remains on the hard drive, deleted or not. What is taken away when a file is deleted is the hard drive’s knowledge of the file’s location. If the hard drive doesn’t know where the data is, the data can never be found. This gives the appearance of being deleted, even though the data remains on the hard drive until overwritten by new information.
If you’ve lost data, and are wondering if you can get your information back, this is great news! Our data recovery specialists know just how to finesse those file tables to find and retrieve the missing data.
When permanently deleting data is your goal, the best method is overwriting. You need to write over the deleted data to make sure the information is gone for good and cannot be retrieved. There are hard drive wipe software options to accomplish this, just be sure to use a zero-fill method.
Don’t forget about your backups
Backing up data is an important part of computing, and something we encourage you to do regularly. Fortunately, many modern operating systems and devices have built-in backup technology.
This technology, while helpful, can produce some interesting results. Consider this, you take a picture on your phone and within seconds the photo is backed up to your Google photo account. You like the picture, so you text the photo to your friend and email the picture to your cousin. You also decide to upload the photo to your computer for editing. Once uploaded to your computer, the photo is automatically backed up to iCloud via Time Machine and to your external hard drive.
Without even realizing, you’ve created nearly 10 separate digital copies of the same photo. And for certain pieces of data, that’s ok. Having treasured family photos saved in many places, whether you realize the backup is happening or not, is a great thing if you lose your data.
But there are other types of data, like financial and legal documents, for which you don’t want multiple digital copies floating around. Maintaining a record of and control over this type of data can be a challenge when much of the software and hardware we use today are designed to produce copies of information to prevent data loss.
Whether your goal is to share family photos or keep your personal information secure, understanding how hard drives work and remembering where the information is stored and backed up is critical. Deleting data isn’t always simple! But learning how to manage your digital footprint will help keep you in control.
When you didn’t mean to delete your data
Let’s be honest, though. Things happen, and no matter how well you understand hard drives or how meticulously you maintain your backups, accidental data deletion happens.
If you’ve accidentally deleted data, all is not lost. There are data recovery specialists who can help! Contact a data recovery specialist today to get your information back and regain control of your data.