Oxford team claims secure method for remote quantum computing

Scientists at the University of Oxford say they have shown how to run quantum computations on a remote machine without exposing the user’s data or algorithms, a step they argue could make secure “quantum computing from home” possible. The results, published in Physical Review Letters, describe a “blind quantum computing” experiment linking a quantum server in the cloud to a local client over a standard fibre connection.

“Never in history have the issues surrounding privacy of data and code been more urgently debated than in the present era of cloud computing and artificial intelligence,” said Professor David Lucas, who co-led the team.

“As quantum computers become more capable, people will seek to use them with complete security and privacy over networks, and our new results mark a step change in capability in this respect.” In the trial, lead author Dr Peter Drmota and colleagues connected a trapped‑ion quantum computing server to a client device set up to detect photons via a conventional fibre cable.

The researchers say they performed several computations remotely on the server without the server seeing the inputs, the algorithm or the outputs. Each computation introduced a correction that had to be fed into subsequent steps in real time to follow the algorithm, which the team says they achieved using a combination of quantum memory, photons and statistical analysis.

The client accepted a result only if the observed fraction of failed test rounds fell below a chosen threshold. According to the researchers, the appeal of blind quantum computing is that users do not need quantum hardware themselves; they instruct the server through an interface and receive the results back.

“Using blind quantum computing, clients can access remote quantum computers to process confidential data with secret algorithms and even verify the results are correct, without revealing any useful information,” Drmota said, calling the demonstration a significant step for both quantum computing and online data protection.

While today’s quantum computers are largely confined to experiments, research and training, the Oxford team says its approach could scale as larger, more capable systems arrive, providing a path toward fully verified quantum computing in the cloud. They suggest industries that require strict confidentiality, such as pharmaceuticals, could be early beneficiaries.

Ultimately, they add, commercial client devices could emerge that plug into laptops to safeguard data when accessing quantum cloud services.