I beg to differ: Good quality paper has a life-expectancy
of several hundred years, and so has good quality ink.
Make it waterproof with a zip-lock bag. Make it non-obvious by
folding it.
Even an industial SD card only has 10 years data life expectancy,
your ordinary commercial "quality" one can become shaky after as
little as a year and a "no name" one even sooner.
Hm, I think you compare some spaceship technology paper and ink with
noname sd car manufacturer. I have no idea where I can get that eternal
paper and ink that never wares while active use, but I have 3 n-year old
1 gb sd and microsd cards that I can still use without problem. I have
even older working 256-mb flash drive...
I still don`t get why I shouldn`t use encrypted keyfile for the purpose
of destroying information. You tell me that there is an alternative.
That`s good! But what`s wrong with my way?
it is not resistant to
water, it could be easily copied by attacker and not by you (if you
don`t trust electronics)...
Huh? And the SD card cannot be copied?
SD could be copied of course, but not as easy as to make a foto of piece
of paper.
And why shoudl the attacker
have any advantage here?
Because then I cannot destroy encrypted container with destroying my
copy of keyfile.
and I don`t mention convenience like
ability to carry as many keyfiles as I want without being looking
strange, etc.
Also, for example, 1024 or 16k letters is far more better for
security than 50+what_you_can_remember letters for passphrase...from
"cryptographical perspective", please excuse my ignorance :)
They get hashed to 160 bits by the passphrase input. From
about 30 characters onwards, you do not get a better hash.
That is another thing I wanted to talk about later, but you mention it
here. Quentin Lefebvre wrote before: "it's worth remembering hash
algorithms are ignored with key files in plain mode, so that the
--hash=sha512 is not effective and actually equivalent to --hash=plain
in this case".
I have three questions:
1. Are you saying passphrases longer than "about 30 characters" are
useless with plain mode?
2. So it is more secure to remove --key-file=- and pass unencrypted
keyfile as passphrase but make sure I have no new lines there? Then I
could use --hash=sha512 and it would be effective?
3. When I try to replace "--hash=sha512" with "--hash=plain", I cannot
mount mapped device, so it is not the same. Em?
I may write very stupid things here, so I apologise in advance for that
:)
It really depends on the details of the scenario.
Ok, let`s stay in IT security. It could be some sort of timer, and I
must remotely do something before data get destroyed (phone special
number, go to website and type password, send email, pay bills, etc),
then timer resets.
>>3. Attacker can attach a hidden camera behind me while I typing
>>password (or do similar approach) and then get a copy of encrypted
>>data (it is far easier than get full root access)
>
>Oh? Just have the attacker look with the camera while you type
>in your root password...
Root password != full access right away. Also, they could "catch"
one password and not other.
Sorry, but irrelevant. If you do not notice, they have all the time
they want. If you notice, then even "right away" is not fast enough.
There may be small residual benefit from scenarios where you notice,
but only a short time later.
I could be in video-controlled area for a short period of time, and they
can get video and data copy far later, when it is obvious it is needed.
But I agree, this is not very practical case. In other hand, not
impossible :) IDK
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