On Sun, 2019-01-27 at 20:46 -0800, jdow wrote:
On 20190127 14:44:52, Patrick O'Callaghan wrote:
> On Sun, 2019-01-27 at 19:56 +0100, Wolfgang Pfeiffer wrote:
> > > Given that encrypting the disk means (at a minimum) reading the entire
> > > contents and rewriting it,
> > No. I don't think data is written and rewritten. See below.
> If it's not being read and rewritten, it's not being encrypted. It's as
> simple as that. A cryptosystem that doesn't read the plaintext? How
> does that work?
Give me an image if the disk and after suitable time and effort I have access to
the whole thing if only the directory entries are encrypted. So the tool in
question gives a false sense of security at best.
If that's indeed what it does, I agree.
Another point: several people have mentioned using /dev/urandom. It's
important to note that this is a *pseudo-random* generator. It starts
from a random seed, but from that generates a completely deterministic
pattern. If you have the seed, you have everything. And since the idea
here is to overwrite the disk, the first part of which contains
"plaintext" that follows a regular layout (partition table etc.) it
makes the task of decoding the disk even easier as that's the only part
you would actually have to analyse at a physical level.