Bizarre device uses 'blind quantum computing' to let you access quantum computers from home

Researchers have developed a new communication paradigm that can let them securely connect a PC to a quantum computer over the internet.

Known as "blind quantum computing," the technique uses a fiber-optic cable to connect a quantum computer with a photon-detecting device and uses quantum memory — the equivalent of conventional computing memory for quantum computers. This device is connected directly to a PC, which can then perform operations on the quantum computer remotely. The details were outlined in a new study published April 10 in the journal Physical Review Letters.

Quantum computers offer the potential for processing power that far outstrips conventional computers. But they are also incredibly delicate and need to be cooled to near absolute zero to prevent external interference with the quantum states. Conventional computers can connect to servers over the internet to store information and access processing power. However, there is always the risk that information could be intercepted. 

Some companies offer quantum computing services through the cloud, including IBM and Amazon Web Services (AWS), although the scientists argue these aren't 100% secure or scalable. Connecting a PC to a quantum computer using the new method, however, could provide a way for users to run a computation remotely but keep the structure hidden — while enabling verification of the computation by embedding hidden tests.

Related: Quantum computing breakthrough could happen with just hundreds, not millions, of qubits using new error-correction system

The quantum computer in the study used an electronic device called an ion trap. Using electric potentials, singly-charged ions of calcium and strontium (the qubits in the quantum computer) were captured by electrodynamic fields within the trap and then cooled to control the electronic states of the atoms and prevent them from escaping. The photons — which established the link between the quantum computer and the remote computer — were focused through a large objective lens into the optical fiber and then transmitted to the user. 

In blind quantum computing, the user connects to the quantum computer over the internet using a photon-detecting and reconfiguring device to steer the qubits of the quantum computer. Therefore, the input, algorithms and output effectively become concealed from the quantum computer.