How to securely erase data from a thumb (solid state) drive
How do you securely erase data from a thumb (USB/flash) drive?
With traditional (magnetic/spinny) hard drives, it used to be that you could use various tools to simply overwrite with random data, and make it unrecoverable. You even have tools like shred
that can do it for a specific file.
Many of these don't work on solid state devices (which most thumb drives are) because those have less predictable patterns over where data get written.
Does that mean that it's impossible to erase an SSD beyond recovery? Or is there a way to do it? Can you do individual files too, or is it only possible for the whole drive?
Note: I want to still use the drive after the erase, so no melting it in the raging flames of Mt. Doom.
1 answer
Answering your question as written, this is a hardware-specific question. Since solid-state storage chips typically keep the details of which cells are being used to write data hidden from the OS, never mind the user, in order to be sure you've erased any unit of data beyond recovery, your hardware vendor would need to have written that functionality into its drivers somehow, and then you'd need a way to access it, from Linux. And you would need to trust that your hardware vendor is both competent at this task (which is rarely verified by consumers, after all) and uncompromised by the threats you're concerned about.
In my experience, the best approach is to encrypt a solid state device before ever using it, and store the key, or a passphrase used to decrypt the key, on a device from which it is more difficult to recover. Wetware works well.
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