DoD Computer Erasure Disk Standards

A DoD computer erasure disk must satisfy a rigorous Department of Defense approved standard for eliminating any possibility of data recovery from a computer disk.

These stringent requirements result from the fact that standard data deletion processes do not prevent data from being recovered. A deleted file remains on the disk. The space it occupied is simply made available to be used again. The actual contents of the file are still on the drive and remain there until those sectors are overwritten.

There is some debate about how many times a file needs to be overwritten and the sequence of characters used. Depending on the sensitivity of the information involved the number of wipes required to meet the standard may increase to 10, 20 or even 30.

There are some who argue that the DoD disk erasure standard isn't adequate. They point out that if errors occur during the process, or if the program is unable to overwrite a sector then cleansing will be incomplete. There remains a possibility that data can be accessed, even if it cannot be overwritten. If a sector cannot be overwritten, degaussing or media destruction is required.

Except for situations of extreme secrecy and national security the DoD computer erasure disk standards are an effective way to wipe a system. Software compliant with these standards is typically compact and will reliably destroy data. The standard complies with procedural regulation in both the United States and Canada for rendering data unrecoverable.

While there are many free drive cleaners available, the potential cost of not doing the job properly more than justifies the small investment required to have access to the best DOD compliant erasure product available.

Irrespective of whether a laptop or desktop computer has been used for personal or business purposes it should be cleansed using a tool that at a minimum meets DOD erasure standards before donating it or selling it. In the absence of such measures information can persist for years and be accessible to whoever has access to the computer and an inexpensive data recovery tool. Data cleansing tools should be included in everyone's portfolio of laptop security software.