> Russell Nelson <[EMAIL PROTECTED]> wrote:
>>> If quantum computers make brute-force cryptanalysis tasks easier,
>>> don't they also make brute-force cryptographic tasks easier as well?
At 01:12 AM 10/18/1999 -0400, Vin McLellan wrote:
> The problem to worry about, of course, is that maybe not everyone is
>going to have access to the same oracle.
....
> Consider what was involved when the NIST lab at Boulder created a
>qubit a couple of years ago. As I recall, to get their qubit they had to
>trap a single atom with missing electrons (an ion) and two energy levels by
>nailing it down with an array magnetic and electric fields at minus 273
>degrees C.
For instance, will it fit in your palmtop or smartcard? Probably not.
It's not clear that, in practice, it will be possible to get
high enough resolution out of quantum computers to affect crypto -
a resolution of 20 bits is enough to annoy smartcards by forcing
the encryptor to use more key bits, but doesn't bother other computers.
A resolution of h-bar is ~10**47 or 150 bits, but by the time we get
that much resolution, it probably won't bother palmtops much,
except maybe for RSA key generation. Quantum devices with
resolutions like that probably aren't small or portable
However, if you can get much bigger resolution improvements
out of quantum devices without some way to use
lower-resolution devices in parallel while still collapsing
one big waveform in some kind of Quantum Black Magic.
Hard to say if that will be portable or not, or affordable
except by large organizations (particularly, even with Moore's Law
constantly making things cheaper, will the cost be
some large multiple of the cost of small portables,
Pocket Area Networks, Pencil Area Networks, RF grocery tags,
you-are-here broadcasters on store shelves or license plates, etc.
Thanks!
Bill
Bill Stewart, [EMAIL PROTECTED]
PGP Fingerprint D454 E202 CBC8 40BF 3C85 B884 0ABE 4639
