Why, all of a sudden, is everyone concerned about secure file deletion? I hesitate to say it’s a sign of the poor economy, but perhaps people consider it even more important to protect their personal information when the idea of losing control of their assets—and their lives–through the incompetence of corporate “managers” and well-intentioned but clueless politicians is more abhorrent than losing control through the outright thievery of Internet gangs. It’s weird. I harped on people about securing their data all along and mostly, my advice fell on deaf ears. Now people are worried. And it’s not because they see more spam email phishing attempts, it’s because they feel they can’t trust anyone anymore, not their formerly respected captains of industry, and certainly not their elected officials.

But, I digress. This post is about security tools, not politics, so I’m now officially off of my soapbox.

I recently posted an article about SDelete, a tool that can be used to securely delete files and folders on a hard drive. There’s another little known, useful tool that has been built into the OS since Windows 2000: cipher.exe. Microsoft provides the following in Knowledge Base article 315672:

How to Use the Cipher Security Tool to Overwrite Deleted Data

To overwrite deleted data on a volume by using Cipher.exe, use the /w switch with the cipher command. Use the following steps:

1. Quit all programs.
2. Click Start, click Run, type cmd, and then press ENTER.
3. Type cipher /w:driveletter:\foldername, and then press ENTER. Specify the drive and the folder that identifies the volume that contains the deleted data that you want to overwrite. Data that is not allocated to files or folders will be overwritten. This permanently removes the data. This can take a long time if you are overwriting a large space.

One more tool you can use to mollify your paranoid clients.

NIST gets the prize: One pass is enough to delete data such that it can not be recovered.  A paper published in December last year; “Overwriting Hard Drive Data: The Great Wiping Controversy” by Craig Wright, Dave Kleiman and Shyaam Sundhar R.S. as presented at ICISS2008 and published in the Springer Verlag Lecture Notes in Computer Science (LNCS) series, proves beyond doubt that data can’t be recovered from a wiped drive even if one uses an electron microscope. As Craig Wright puts it in a post on the SANS Computer Forensics blog:

Although there is a good chance of recovery for any individual bit from a drive, the chances of recovery of any amount of data from a drive using an electron microscope are negligible. Even speculating on the possible recovery of an old drive, there is no likelihood that any data would be recoverable from the drive. The forensic recovery of data using electron microscopy is infeasible… The fallacy that data can be forensically recovered using an electron microscope or related means needs to be put to rest.

That sure makes life easier for those of us who have to deal with secure deletion of sensitive data. I’ll use my copy of Darik’s Boot and Nuke (DBan) with one pass from now on and get those retired hard drives wiped in no time.