Hackers may be able to “vandalise” other people’s results on a quantum computer, say researchers, who warn that the problem will only get worse as devices become larger and host more users simultaneously, unless manufacturers plug the security gap.

Sharing access to expensive computing hardware is a common practice, whether on classical supercomputers or exotic quantum chips. Classical devices often run multiple programs for many different users at once, but there are security measures in place to prevent one user from affecting another.