|
 |
On 18/08/2011 03:57 PM, Darren New wrote:
> On 8/18/2011 1:29, Invisible wrote:
>>> Which device was this? I could use something to stick my passwords on.
>> ...the irony... it burns...
>
> What's ironic about wanting to put passwords or private keys on an
> encrypted portable medium?
You want to password-protect your passwords? That's just crazy. (The
idea of a password is that you're supposed to /remember/ it. Which makes
it impossible to ever steal.)
Password protecting private key files is another matter. Having the
keyfile on a portable device means it's always with you, you can use it
like a physical key, but if you lose it, the password should stop
anybody else pretending to be you.
>> OK, for anyone else wanting to duplicate my results:
>
> Thank you!
No problem. There's no charge for this service. ;-)
(Just waiting for you to complain that you can't order from the USA now...)
>> Not necessarily. I'm pretty sure you can buy off-the-shelf components
>> that
>> run crypto primitives like AES.
>
> I was thinking it would likely be a core, not a component as such.
I'm not so sure about AES, but its predecessor DES is very, very easy to
implement in hardware. Literally *all* you have to do is a few XOR
operations, rearrange the bits slightly, and implement a few S-boxes.
Each S-box is probably a dozen logic gates. That's really very, very
little hardware at all. An 8-segment display driver probably has more
transistors in it than that. And it's probably very much faster than
doing this in software, where things like complicated bit permutations
are fairly expensive.
(My recollection is that AES involves finite field arithmetic that's
quite fiddly in software, but probably very simple in hardware. I don't
remember a great amount of detail though.)
>> Fundamentally though, it doesn't matter whether AES is in special
>> hardware
>> or in firmware. The point is, the encryption is transparent to the
>> host PC.
>
> Right.
Mmm, I wonder if it's immune to side-channel attacks? >:-D
Post a reply to this message
|
|
