Governments bans on quantum computer exports have no basis in science

Imagine if governments around the world announced restrictions on the sale of rulers that are 34 centimetres long. You would be pretty confused, given there doesn’t seem to be anything special about that length – and 34cm rulers don’t exist.

Such legislation would be ludicrous, but something similar has been enacted for quantum computers in several nations (see “Multiple nations enact mysterious export controls on quantum computers“). The restrictions – which limit the export of computers with 34 or more qubits, or quantum bits, and error rates below a certain threshold – are puzzling, as such devices have no practical use, according to all published research.

But the very specificity of the number suggests some thought behind it. Clearly, someone, somewhere, is worried about nefarious use of these devices – most likely their potential to break widely used encryption methods – and wants them restricted in the name of national security.

So what is going on? There are two possibilities here: either they are wrong, as scientific evidence suggests, and pointless legislation is now being cut and pasted across the world, or they are right and have now alerted their adversaries that this is a number worth paying attention to. Both possibilities seem counterproductive, but without access to the research behind these restrictions, it is impossible to say.

One of the great strengths of science is that it is an open endeavour. For all its faults, peer review allows us to harness minds around the world to scrutinise and improve research. Our approach to making policy should be no different.

The Intergovernmental Panel on Climate Change shows just how powerful this can be. By publicly synthesising research, it has allowed policy-makers to understand what needs to be done to tackle climate change – and allowed others to use that evidence base to analyse policy decisions. Equally, published research during the covid-19 pandemic allowed for a public discussion on rules being imposed on us. Simply plucking a number from the air, as seems to be the case with quantum computers, is no way to govern.