Quantum physics may lead to secure cloud computing

Gizmag : With the rising popularity of “cloud computing"—the sharing of resources, software, and information over the internet—security is a growing concern. To preserve privacy while users interact with remote computing centers, researchers in Austria have combined quantum computing with quantum cryptography in a process called blind quantum computation. According to Stefanie Barz and colleagues, whose paper was published online in Science on 20 January, users prepare qubits in a state known only to themselves. They send the qubits to a quantum computer, which entangles and then manipulates them to execute a particular computation, whose results are sent back to the users. The users’ input, output, and algorithms are never disclosed to the company doing the computations, and no eavesdropper can read the qubits without knowing their initial state. The researchers emphasize, however, that their experiment is only one step toward unconditionally secure quantum computing.