Blind quantum computation using the central spin Hamiltonian
In the near future, quantum computers at their early development stages will likely be available only at a few leading research facilities. Others who wish to access the quantum computers may still do so via delegated quantum computation schemes. Typically in such a scheme, a client sends instructions for the computations to the server which hosts a quantum computer. The server then performs the computations and returns the outcomes to the client. A desired feature of delegated quantum computation scheme is blindness, which allows the client to send the instructions without actually revealing the computation circuit. We propose such a scheme inspired by the central spin Hamiltonian. In this scheme, the client encrypts their data into a single "central" spin, which is communicated back and forth with the server. The state of this central spin controls the dynamics of the bath spins, which are the computational qubits on the server. Security of the scheme is ensured by the indistinguishability of nonorthogonal quantum states.