[SOLVED] zero wipe a mapped device i.e /dev/mapper/name

tecjykidd · 08-30-2018, 10:55 PM

Hello ya'll

I've seen some articles online on encrypting partitions with cryptsetup.

Zero wiping an encrypted mapped device is optional, but some will recommend it. Is there a reason or some benefit to doing this? Thanks for reading

lougavulin · 08-31-2018, 09:44 AM

It is the same reason to randomly wipe your partition before encrypting your device.

Once your device is encrypted and then you write stuff on it (for example install your system). If someone look at your device, the data you write encrypted looks random, with no means.

By wiping before randomly or after with zeros, the whole device seems to contains random data.

tecjykidd · 08-31-2018, 10:50 PM

Still a little confuse. Even if I don't wipe with zeros, isn't the encrypted partition already gibberage if someone tries to look at it?

syg00 · 08-31-2018, 11:08 PM

Yes. It probably depends who you are trying to defend your data against.
Previous structure might be discernable even from patterns in the encryption on top of old data. But only by someone like the NSA. Note I said "structure" (possible existence of partitions, filesystem ...), not the data itself.

For a normal person with normal data and fighting against normal criminals, encryption alone should be more than enough.

tecjykidd · 08-31-2018, 11:16 PM

Thank you lougavulin & syg00 for the replies. I understand now.