3 ms·
The point of using random instead of zero is that it's harder to see which parts have been overwritten and which parts haven't been.
by shin_lao 11y ago
The point of using random instead of zero is that it's harder to see which parts have been overwritten and which parts haven't been.
- BCM43 11y agoWhen is that useful?
- _petronius 11y agoIn the case of a partial erasure (eg, maybe someone disconnected the power during the write, to stop the write from completing), I guess it would make it harder to prove someone had tried to erase (and therefore possibly hide/destroy) information.
- deleted 11y ago[deleted]
- lucaspiller 11y agoOn the other hand that makes it indestingishable from encrypted data. What is worse? "Give us the encryption keys" "It's not encrypted, I used /dev/urandom" vs "Yes, I wiped it"
- DanBC 11y agoYou're supposed to overwrite the entire disc. And random data is very easy to see. The people who propose using multiple overwrites are clear that they're talking about making it harder to recover bits. (They're wrong, but it's what they say.)
- pflanze 11y agoAlso, some (flash) drives are compressing data on the fly. Writing zeroes to such a drive might just not actually write anything at all to the flash cells except for some run length descriptors (numbers). Since the worry seems to be speed, here's a tool I wrote to get random bytes about as fast as drives can accept (well, at least spinning disk drives, there might be some flash drives that are faster): https://github.com/pflanze/fastrandom https://github.com/pflanze/fastrandom I'm expecting you to figure out where this tool goes wrong and produces predictable bytes yourself. Also, please tell me if you do :) Anyway, even if it isn't secure, it will be enough to foil compression algorithms.