Twenty years before most scientists expected it, a commercial company has announced a quantum computer that promises to massively speed up searches and optimisation calculations.

D-Wave of British Columbia has promised to demonstrate a quantum computer next Tuesday, that can carry out 64,000 calculations simultaneously (in parallel "universes"), thanks to a new technique which rethinks the already-uncanny world of quantum computing. But the academic world is taking a wait-and-see approach.

D-Wave is the world's only "commercial" quantum computing company, backed by more than $20 million of venture capital (there are more commercial ventures in the related field of quantum cryptography). Its stated aim is to eventually produce commercially available quantum computers that can be used online or shipped to computer rooms, where they will solve intractable and expensive problems such as financial optimisation.

It has been predicted that quantum computing will make current computer security obsolete, cracking any current cryptography scheme by providing an unlimited amount of simultaneous processing resources. Multiple quantum states exist at the same time, so every quantum bit or "qubit" in such a machine is simultaneously 0 and 1. D-Wave's prototype has only 16 qubits, but systems with hundreds of qubits would be able to process more inputs than there are atoms in the universe.

Scientists in the world's many quantum science departments are looking anxiously at whether the demonstration - linked to a computer museum in Mountain View California, will vindicate their work or cast doubt upon it.

"This is somewhat like claims of cold fusion," said Professor Andrew Steane of Oxford University's Centre for Quantum Computing. "I doubt that this computing method is substantially easier to achieve than any other."

Others are more enthusiastic: "I'll be a bit of a sceptic till I see what they have done," said Professor Seth Lloyd of MIT. "But I'm happy these guys are doing it." Lloyd is one of the scientists who helped develop the "adiabatic" model of quantum computing which D-Wave's system exploits - a method which D-Wave believes will sidestep the problems which have restricted progress in quantum computing so far.