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Do you have a new computer? What are you doing with that old one? Time to send it to e-waste for recycling or give it to a friend to reuse? Before you do that take a moment to think about what might be on that hard drive. Banking information? Credit card numbers? Passwords? Videos that it would be better if the world didn’t see them? Perhaps you think, “no problem I’ll just delete those”. Did you know deleting files doesn’t actually make them unreadable on the drive? It just makes them available to overwrite; they can still be easily retrieved and read.
Be safe: don’t pass any hard drive to anyone without blanking it first, using real military-grade blanking, so you know that data is truly gone. For older style rotating hard drives there are a number of ways of blanking them. Some years ago the preferred choice was DBAN, (Darik’s Boot and Nuke), a self-contained ISO file that you could download and put on a CD, DVD or a USB stick and then run it to blank a hard drive. DBAN development ended in 2015, that free software project was sold to a commercial company and there hasn’t been a new release in five years. DBAN was nice and simple. It used a blanking program called dwipe that ran on top of a Linux kernel.
The great thing about free software is that it is easy to fork and so dwipe has become nwipe, developed by Martijn van Brummelen. It is easy to get too. To blank a drive you have to run it from somewhere other than the drive being blanked. If you want to blank the main hard drive on a computer then you need to run it from some other media, like a CD, DVD or USB stick. One way to get nwipe is to get it pre-packaged, such as in the All-in-One System Rescue Toolkit (AiO-SRT), put out by Paul Bryan Vreeland. It is easy to download the AiO-SRT, make a disk and then boot it up to run nwipe, right from the AiO-SRT desktop. The current version of AiO-SRT is based on Lubuntu 16.04 LTS, though and so newer hardware may require a newer Linux kernel to run it.
nwipe is also available as a package in the Ubuntu repositories. That means you can add it to any ‘buntu flavor running as a live session and run it using the newest kernel, which will support newer hardware. I have done this with Lubuntu 19.10, being run from a USB stick. It can be installed from the package manager or from the command line: $ sudo apt install nwipe and it installs in seconds, being only 32 kb in size. Running it is equally easy: $ sudo nwipe and it will open in a terminal window with a simple ncurses interface. Just arrow key to the drive to be blanked, space bar to select and shift+s to start it running.
The default blanking pattern is the DoD Short (US Department of Defense 5220.22-M short 3 pass wipe, using programmed passes 1, 2 & 7), using the Mersenne Twister pseudo random number generator. In case you prefer another method, the interface allows choosing any one of seven others: • Zero Fill - Fills the device with zeros, one round only. • RCMP TSSIT OPS-II - Royal Canadian Mounted Police Technical Security Standard, OPS-II • DoD 5220.22M - The American Department of Defense 5220.22-M full 7 pass wipe. • Gutmann Wipe - Peter Gutmann's method (Secure Deletion of Data from Magnetic and Solid-State Memory). • PRNG Stream - Fills the device with a stream from the PRNG. • Verify only - This method only reads the device and checks that it is all zero. • HMG IS5 enhanced - Secure Sanitisation of Protectively Marked Information or Sensitive Information If nwipe is being run from a ‘buntu disk then any screensavers should be disabled to make sure nwipe completes its task unimpeded.
How long does it take to blank a drive? That all depends on the speed of the processor and the size of the drive, plus the method used. I was recently able to blank a 250 GB drive with an Intel Core i5 dual core CPU running at 2.30 GHz, in about five and a half hours. A 1 TB drive may take 24 hours. When it is finished, the nwipe interface gives a “success” report , which provides some confidence that it is done right. Checking the drive with Gparted or the KDE Partition Manager will show the disk is all “unallocated space”, if it is done right. There will be no operating system, no file system and no partitions present on the blanked drive.
nwipe is used for rotating hard drives, but it is not used on solid state drives (SSDs). Those newer style drives can be blanked with Parted Magic , which has a utility that can do it, called Secure Erase. Secure Erase can also blank rotating hard drives, too. It is probably worth noting that all these blanking methods only work on drives that still work (even if they have errors on them). If a drive no longer works, it is best to physically destroy it, before recycling it.
Conclusions nwipe gets your drive safely sanitized and ready for recycling or reuse. It is easy to get in several ways and simple to use. Best of all, it works!
Links nwipe home: https://github.com/martijnvanbrummelen/nwipe nwipe on Launchpad: https://launchpad.net/ubuntu/+source/nwipe All-in-One System Rescue Toolkit home: https://paul.is-a-geek.org/aio-srt/ Parted Magic Secure Erase: https://partedmagic.com/secure-erase/