True unpredictability requires complex planning. Current methods of generating “random numbers” for data encryption fall short. These often depend on codes involving prime numbers which ordinary computers cannot crack. But quantum computers might theoretically unscramble a slew of data encrypted by business.

You have to admire the marketing smarts of the UK’s Cambridge Quantum, which is backed by Honeywell of the US. It has launched a “quantum-enhanced” cryptographic key generation platform, which it hails as the first commercial product that only a quantum computer could create.

To some potential customers this will sound like fighting fire with fire. They fear that quantum computers — which rely on sub-atomic uncertainties for incredible speed — may soon stop crashing for long enough to decode secret data.