It’s a brave new world in this digital era, with more data stored electronically and flowing across the internet than – not too long ago – it would be possible to consume in several lifetimes. For most people, digital is now a way of life – everything from shopping and banking to working, organizing, researching and entertaining is accomplished through an electronic device.
Of course, you don’t want all of your digital information shared with the world. Electronic security is essential, and aside from password protection and encryption, data deletion is a common way to remove information that shouldn’t fall into other hands. But did you know that simply deleting files from your hard drive, or emails and web content through your browser, is not enough to actually get rid of the data?
There are tools out there for recovering deleted data at several levels. Some of them, such as forensic computer tools, are used by government and law enforcement agencies for investigation. Others are used by hackers to gain access to sensitive information, resulting in damage and data theft. (To learn about security in general, see The 7 Basic Principles of IT Security.)
Hard Drive Storage: What Happens to "Deleted" Files
Most everyone knows when you "delete" a file on your computer, it doesn’t leave your hard drive. Instead it goes to the trash or recycle bin. But even if you empty the trash folder, those deleted files still reside in your computer.
Deleting files from a hard drive only removes the "pointers" that make it easy for you to access the data. The actual data is still stored, and there are several fairly simple ways to access them. If a hacker gains remote access to your hard drive – a very common method for stealing private information – they can use simple file restoration programs to get it all back. This holds true for personal computers, workstations and even discarded equipment with hard drives that have been deleted.
When You "Delete" Your Emails
Another fairly common piece of knowledge is that nothing on the internet is ever truly gone. Immense caching – a storage system that saves all content and previous versions – through major search engines like Google ensures that the digital collective is preserved constantly. When you delete email messages (and empty your "Trash" folder), it may seem like there's no way to get that data back, but that isn't entirely true.
The good news here is that for the most part, hackers can’t access emails that are deleted permanently from the Trash folder. However, email ISPs keep backup copies of client inboxes, and in some cases these deleted messages can be retrieved, usually through a court order.
Hackers typically use other methods to break into email and steal sensitive information, either through phishing scams, password breaks or remote access that lets them log into your live account and read through messages.
What About Text Messages?
It would seem that deleting text messages works about the same as deleting email, but that often isn’t the case. Today’s smartphones are highly sophisticated machines. They have larger hard drives, capable of storing more data – and that includes deleted text messages.
Forensic technology is available to recover deleted text messages from phone hard drives. And while cell phone companies claim not to store the contents of text messages, court-ordered subpoenas can still turn up records of texts.
As with computers and desktops, cell phone data is never truly gone. And if your phone is stolen, the thief may be able to access deleted texts.
Protecting Your Deleted Data
Making deleted data practically inaccessible from hard drives on your computer or smartphone is not an impossible task. It simply requires a few extra steps. For computers, you can use a wiping program that "scrubs" or overwrites all of the unused data spaces on your hard disk where your deleted files used to be.
There are several free programs that can accomplish this task. Some of the most popular include CCleaner, Spybot Search & Destroy, Eraser and BleachBit. (For more on secure hard drive erasure, see Destroying Data DIY.)
When it comes to smartphones, the key is to take steps to prevent theft and have precautions in place in case your phone is stolen. Make sure you lock your phone with a strong password that will at least slow down a thief. And have remote wiping capabilities installed so that, if necessary, you can erase the contents of your phone’s hard drive from any computer.
Being aware that deleted data is never really gone is an important first step to protecting your sensitive electronic information. Even deleted files can fall into the wrong hands. Take the steps to ensure they don't.