Re: interesting article on quantum cryptography

Douglas A. Gwyn <DAGwyn@xxxxxxxx> wrote:
+---------------
| There is "quantum computing" (QC), which should apply to any algorithm,
| with known advantages over conventional computing (once QC is available
| on a large scale) in the case of *some* kinds of algorithms. QC could
| be applied to any crypto algorithm, "XOR-based" or not.
+---------------

Well, *some* kinds of QC perhaps, though probably not all.
E.g., it's not at all clear [at least, not to me] that
adiabatic quantum computation (AQC) is *ever* going to
be of any use at all in cryptography, since when you
scale up to large numbers of qubits the energy levels
between solutions start getting *very* small, so that
the best you end up with are approximate solutions.
[And "approximate" doesn't cut it in modern cryptography.]

It nevertheless might someday be of quite considerable use
in certain NP-hard problems such as the "max clique" graph
problem [where a good approximate but not exact answer still
has commercial value], but that's another story...


-Rob

-----
Rob Warnock <rpw3@xxxxxxxx>
627 26th Avenue <URL:http://rpw3.org/>
San Mateo, CA 94403 (650)572-2607

.