Quantum computers: Be afraid, be very afraid …

November 15, 2007

Vista busy cursor Quantum computing is being touted as a spectacular advance that will take computing power to a level we can barely imagine today. Leveraging the superposition of quantum states to achieve the equivalent of a massive array of parallel processors, the quantum computer will be able to do in seconds what today’s best computers couldn’t do in 20 years.

Now that’s a good thing, right? Well … isn’t it?

Of course it is, in many ways. Computational problems that look too tough to crack now will become easy to tackle. We’ll be able to do cosmological modelling to solve the riddles of the big bang. We’ll track down dark matter and then dark energy the week after that. We’ll be able to turn our attention from the large to small scale and test models of physics based on string theory.

Medicine, mathematics, science, engineering – no computational problem will be beyond us ever again.

And the bad guys won’t be able to hide their secrets from the authorities any longer. The quantum computer will crack their pesky encryption keys in seconds flat. Yay!

Well … yay! YAY!!! Yay … ?? What?

Oh, that’s right. The good guys won’t be able to keep their stuff secret any more either. Soon enough anyone will have access to the computing power to break any encryption-based privacy or security system. No-one will be able to keep any secrets, whether for good or for evil purposes.

Don’t bother with a long hard-to-remember password. Any well-connected hacker can still break into your on-line bank account.

Yay bloomin’ yay.

What’s it going to be? The 3 million bit encryption key, or stuff your cash under the mattress?

OK, I’ve taken a slightly flippant tone at the end there, but there is a very serious point. Our crypto technology, that so many of us rely on for perfectly legitimate uses, depends on the fact that cracking an encryption key is a 20 year job for the best of today’s computers. As computer power increases we’ll need to keep lengthening our encryption keys to keep the job out of the reach of the computers of the day. But what happens when there’s a “quantum leap” in computing power? Do we have to suddenly start using unwieldy long encryption keys on our home PCs just to be sure our data can’t be cracked? And do we have to start panicking about everything we’ve encrypted in the past, which is now as easy to read as plaintext to a hacker or to the authorities?

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  1. Quantum crypto does not protect from hacking ones encryption, at least not as it is now envisioned. I am pretty sure qauntum crypto already exists, or at least is way beyond quantum computing, but I am not up to speed on the field.

  2. Dennis,

    Well, you are right about that. And in fact, quantum crypt (as far as I’ve seen…but I’m no expert) only applies to creating a secure link for sending data between 2 points. In other words, a hacker who gains access to any computer sytesm / network with a quantum computer would (in theory) only be limited by the bandwidth of his connection to that remote server in his ability to decrypt and steal info. Quantum crypt from all I have seen only provides a secure linking technology between 2 physical points in the world, I haven’t heard of any tech that can protect info just sitting on some server or servers.

    I think it very likely that quantum computers will be a controlled access technology with very stringent restrictions on who can access them for this very reason. I doubt that high school and college students (or anyone else) will have ready access to that technology (and that group comprises the vast majority of black hat hackers it seems). Although I recently read about one computer maker that is attempting to release a commercial quantum computer within the next 12 months. (There seems to be some argument over whether it’s a true quantum computer or not though…we’ll see.)

  3. I already stash my cash under the proverbial mattress. I don’t trust my life’s saving in banks. Not worth the interest.

  4. Robert, thanks very much for that. I hadn’t heard of quantum cryptography.

    There is still a concern that from the point when quantum computing becomes a reality, no-one can rely on material they encrypted in the past still being secure. It is unlikely they can replace all their past crypto with quantum cryptography overnight so there will still be some exposure for a while.

  5. Actually….just YAY. Although quantum computers certainly have the potential to make digital security challenging, there is a technology (already working in labs across large distances) that will come to the rescue…quantum cryptography. And this one doesn’t depend on some “unbreakable” encryption to protect data. Rather, it depends on the principles of quantum entanglement to ensure that data is not viewed except by the intended recipient.

    If someone “taps into” a quantum encrypted datastream on its way from point A to point B, it will be detected by the recipient pretty much instantly. And…there is no way to avoid this. No amount of clever hacking and no amount of computer power can overcome this because its a limitation of physics…so…unless we have some breakthrough that makes it possible to read the state of quantum entangled data without changing it, the data will be safe. Right now physicists have come up with a theoretical way to do this…but it would only work if the “thief” were in the same room as the intended recipient. Not exactly an “ideal” situation for a data thief. LOL.

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