Quantum computing

In the recent issue of Scientific American Scott Aaronson has an article presenting the features of quantum computers. It turns out that although there are certain things that such a computer would be able to do very efficiently it will not be able to solve all NP or NP Complete problems.

Factoring large numbers is however something a quantum computer could do efficiently. The author believes that this will be primarily application of quantum computers will be in physics for making more precise calculations of quantum states. Hope he is right, but i fear that the big monetary rewards for cracking cryptographic secrets used in e-commerce and banking may well be the target in the long run. Once a commercial quantum computer device would reach the market it could render current cryptographically secured data open.

I might be too pessimistic. I remember discussing this with a colleague involved with banking systems at a conference just after reading the paper by Peter Shor around year 2000. My colleague did not think that it posed any real threat although I'm not fully convinced that he ever understood the implications. I would however hope that my e-commerce transactions are kept safe in the future also no matter what devices become available.