Quantum Computing Regulation Already?

RMX writes "A new CNet article discusses the possibility of regulating quantum computing. We already see our top tier US VCs investing in Quantum computing companies outside the country. Apparently the feds seem to think regulating the amount of technology that can be sent overseas will make the US safer." From the article: "Only rough prototypes of quantum computers presently exist. But if a large-scale model can be built, in theory it could break codes used to scramble information on the Internet, in banking, and within federal agencies. A certain class of encryption algorithms relies for security on the near-impossibility of factoring large numbers quickly. But quantum computers, at least on paper, can do that calculation millions of times faster than a conventional microprocessor. "

Comments

Setec Astronomy

[TripMaster Monkey]

The summary is a bit fuzy on the details, but here's a telling excerpt from the IBM research article on their quantum computer (link here):

A quantum computer gets its power by taking advantage of certain quantum properties of atoms or nuclei that allow them to work together as quantum bits, or "qubits," which serve simultaneously as the computer's processor and memory . By directing the interactions between qubits while keeping them isolated from the external environment, scientists enable a quantum computer to perform certain calculations, such as factoring, exponentially faster than conventional computers. When factoring large numbers using a conventional computer, each added digit roughly doubles the time to find the factors. In contrast, the quantum factoring time increases by only a constant increment with each additional digit.

This breakthrough completely renders useles the concept of the so-called one-way function, a function which can be executed in polynomial time, but whose inverse can be executed only in exponential time. Basically, this renders just about all public-key cryptographic functions obselete on one stroke.

Interesting times...

Re:Setec Astronomy

[Garse Janacek]

This breakthrough completely renders useles the concept of the so-called one-way function

Not at all -- if you believe that quantum computers will actually work well enough to factor in the real world (many computer scientists don't -- the degree of precision required would be many orders of magnitude greater than any observations of any physical laws have ever been in a real experiment), you're only talking about making some particular one-way functions (in this case, factoring) useless.

In fact, part of the power of quantum computing is that (even without the somewhat less plausible factoring algorithm) we would have real secure encryption -- secure based not on the assumption that factoring is hard (which it may not be), but that quantum physics is true (which it may not be, but a lot of people seem more comfortable with this assumption, at least as far as cryptography is involved).

Re:On Paper?

[Jerry Coffin]

Or even on silicon!

I know you meant this humorously, but it's probably worth noting that in reality, the quantum computers that have been built are NOT in silicon either -- in fact, they're not really based on semiconductors at all.

They're currently (basically) a test-tube full of specially constructed "soup" of (for example) hydrogen and carbon-14 (yes, the same that's used for carbon dating) suspended in chloroform. The results from this are read using an NMR (Nuclear Magnetic Resonance) machine, essentially like those used in medical imaging.

Unfortunately, even the people doing research in this direction admit that there's little likelihood of building NMR based quantum computers of more than a few (half a dozen or so) qubits, which is really too small to do much -- and the NMR-based reading of the results is also quite slow. OTOH, while they may not be particularly practical, they have managed to do real quantum computation this way.

--
The universe is a figment of its own imagination.