An experimental demonstration of blind quantum computing in which the input, computation, and output all remain unknown to the computer is presented, and the conceptual framework of measurement-based quantum computation that enables a client to delegate a computation to a quantum server is presented. 

Almost as intriguingly, the research has been carried out by six researchers from the Universities of Vienna, Edinburgh, Waterloo (Ontario) Singapore and Dublin, three of team being  women.

Various blind delegated computations, including one- and two-qubit gates and the Deutsch and Grover quantum algorithms, are demonstrated. The client only needs to be able to prepare and transmit individual photonic qubits.

The demonstration is crucial for unconditionally secure quantum cloud computing and might bea key ingredient for real-life applications, especially  considering the challenges of making powerful quantum computers widely available.

This is a very strong security guarantee,” says Broadbent,(right) who co-invented the theoretical protocol that was implanted in the recent experiments. “It holds no matter what computational power we ascribe to the ‘adversary’ attempting to spy on the communications.”