from Hacker News

Selling your old laptop or phone? You might be handing over your data too

by devonnull on 4/8/25, 6:01 AM with 10 comments

• by southernplaces7 on 4/8/25, 12:29 PM

  At least if we're talking about laptops, it should be an obvious basic step to completely wipe your drive with multiple passes, though this is a slow job.

  Even easier, just encrypt the whole disk and then "lose" the decryption key. Now it's safe for sale since other's can reformat it despite the encryption that essentially made your data completely irretrievable.

  Less expert with phones, but at the very least format one before selling.

  Edit: having now read the article, encryption is exactly what they recommend for laptops. Excellent.

• by prirun on 4/8/25, 4:56 PM

  I boot Finnix and use dd if=/dev/zero of=/dev/sdx to wipe out drives. Most drives can be wiped out overnight. That fable about needing multiple passes is not true:

  https://datarecovery.com/rd/why-does-it-take-multiple-passes...

  If a drive contained state secrets, I might use /dev/urandom instead of /dev/zero, but those kinds of drives are probably just shredded.

• by atmanactive on 4/9/25, 12:07 AM

  How to deal with an android phone or tablet which you can't switch on anymore but you are absolutely sure there is still your personal data on it?