What Is the Random Data Method?

Random numbers over blackboard

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The Random Data method, sometimes called random number method, is a software-based data sanitization method used in some file shredder and data destruction programs to overwrite existing information on a hard drive or other storage devices.

Erasing a hard drive using the Random Data sanitization method will prevent all software based file recovery methods from finding information on the drive and may also prevent most hardware-based recovery methods from extracting information.

Keep reading for an explanation of how the Random Data method works and a few examples of programs that support this data sanitization method.

How Does the Random Data Method Work?

Some data sanitization methods overwrite existing data with zeros or ones, like Secure Erase or Write Zero. Others include both zeros and ones but also random characters as well, like the Schneier, NCSC-TG-025, and AFSSI-5020 method. However, the Random Data method, as the name suggests, only uses random characters.

The Random Data data sanitization method is implemented in various ways:

  • Pass 1 - ?: Writes a random character

Tip: A data sanitization method that's very similar to Random Data is NZSIT 402. It also writes random characters but it includes a verification at the end of the pass.

Most data destruction tools that provide a Random Data method use it as a kind of do-it-yourself sanitization method, allowing you to customize the number of passes. Therefore, you may see this data wipe method run as little as two passes or as many as 20 or 30 or more. You may also have the option of verification after each pass or just the final pass.

When a program runs a verification on the pass, it means it's verifying that the data was actually overwritten with, in the case with this method, random characters. If a verification fails, the program using the Random Data method will either prompt you to rerun the task or it will automatically overwrite the data again.

Note: Some data destruction programs and file shredders let you customize the not only the number of passes but also the characters that are used. For example, you may select the Random Data method but then be given the option to add a pass of just zeros. However, even though the program might let you customize the sanitization method, anything that deviates too far from what's explained above will result in a method that's no longer Random Data.

Programs That Support Random Data

Lots of data destruction tools and file shredders support the Random Data sanitization method. Some programs that let you erase entire hard drives with the Random Data method include DBAN, Macrorit Disk Partition Wiper, Eraser, and Disk Wipe. Another is CBL Data Shredder, but you have to make the pattern yourself because the Random Data method isn't included by default.

File shredder programs let you erase specific files and folders but not whole storage devices at once. Freeraser, WipeFile, Secure Eraser, TweakNow SecureDelete, and Free File Shredder are a few examples of file shredders that support the Random Data data sanitization method.

Most data destruction programs support multiple data sanitization methods in addition to the Random Data method. You can open any of the programs from above, for example, and choose to use a different data sanitization method if you later decide you want something else.