Guest poster - Randy Ingermanson

People sometimes email me and ask if any of the science in Double Vision is true. I always tell them that most of it is true.

E-commerce all around the world depends on being able to transmit financial information securely over the wires. If you buy a book on Amazon, you need to type in your credit card information. And that needs to be encrypted on your end and decrypted at Amazon, because the information is going to pass through a lot of computers along the way, and there is no way to keep anyone at the computers from peeking at your data!

There is a minor miracle going on here, because in order for Amazon to decrypt your information, your computer and Amazon have to agree on a secret key for encrypting and decrypting. And how are you going to exchange that secret key securely? You might think that you have to encrypt the key and send it to Amazon to decrypt. But that requires a SECOND secret key. How are you going to exchange that SECOND key securely? This problem could continue forever! How do you solve it?

The answer is where that minor miracle comes in. Your computer creates and sends "half of a secret key." Amazon's computer creates and sends "another half of a secret key". Through some mathematical magic, the two computers can then create a whole secret key that nobody else knows about. The mathematical magic relies on the fact that if you multiply two huge numbers together and tell somebody the answer, they will find it supremely difficult to figure out which two numbers you started with.

Unless they have a quantum computer. A quantum computer could solve that problem and break your secret code with Amazon.

I want to emphasize that this has been demonstrated in the lab for a very small quantum computer. IBM did this several years ago, using a quantum computer with 7 "quantum bits".

This means that IN PRINCIPLE, e-commerce all around the world is at risk. If somebody had a large enough quantum computer (with about 10000 quantum bits), they could read all that encrypted mail going around and know everybody's secret keys.

The only thing keeping this from happening is that it's HARD to create a quantum computer that big. In my novel Double Vision, I imagined what's going to happen on the day somebody figures out how to make a large quantum computer. The ideas I used are similar to the ones IBM used to make its quantum computer. Similar, but not identical. I had to make up a little bit of science--but only a little bit.

A lot of physicists believe that large quantum computers will be feasible in the next few dozen years. (And a lot of physicists are skeptical, but history has taught us not to bet against technology.)

When we get large quantum computers, we're going to have to change technologies. And there is a good, secure technology that we could change to. As I said, in order to DECRYPT conventional codes, you need a large quantum computer. But there is another kind of encryption technique that exists NOW that also uses quantum computing to do encryption and decryption. This technique only requires one quantum bit. It is unbreakable but still a bit expensive. Eventually, it'll be cheap enough for everyone.

So what quantum computers take away with one hand, they give back with the other.

Best regards,
Randy Ingermanson

Check out Randy's book, Double Vision, at Amazon.com. For even more fun, go to his website at www.rsingermanson.com