QUANTUM COMPUTER PERFORMS FIRST SUCCESSFUL FACTORING

[ciphergoth]

QUANTUM COMPUTER PERFORMS FIRST SUCCESSFUL FACTORING

IBM SCIENTISTS BUILD MACHINE THAT SOLVES MATHEMATICAL PROBLEMS WITH QUANTUM MECHANICS

NUMBER 15 FACTORED

FACTORS ARE 3 AND 5

http://www.research.ibm.com/resources/news/20011219_quantum.shtml

Comments

Re: Gulp.

[ciphergoth.livejournal.com]

Symmetric crypto keeps working. Grover's algorithm means we have to double our key lengths, but that's no hardship, and really something we should be doing anyway; 256-bit keys are the Right Thing for a variety of reasons. So no need to use that impractical quantum crypto stuff.

But I think Shor has shown QC algorithms for pretty much all the important problems that lie at the heart of public-key stuff. We've got quite used to having public key crypto, it would be sort of weird to lose it again.

Despite this news, I would still be surprised if anyone ever gets, say, a 50-qubit machine going. The equivalent of Moore's Law for quantum computing at the moment seems to be that the machines grow by 1 qubit a year...

Re: Gulp.

[bootpunk.livejournal.com]

> Despite this news, I would still be surprised if anyone ever> gets, say, a 50-qubit machine going.
[my emphasis]

Don't you mean "in the near future"? Or do you think that quantum computing will prove to be too expensive or surpassed by a different technology before it ever becomes scaled sufficeintly?

Re: Gulp.

[ciphergoth.livejournal.com]

It's already surpassed by conventional techniques, and if both conventional and quantum techniques stick to their current rates of improvement then it always will be.

Also, it may turn out to be fundamentally impossible to run a 50-qubit machine without decoherence killing it...