Iterated Gate Teleportation and Blind Quantum Computation

Blind quantum computation allows a user to delegate a computation to an untrusted server while keeping the computation hidden. A number of recent works have sought to establish bounds on the communication requirements necessary to implement blind computation, and a bound based on the no-programming theorem of Nielsen and Chuang has emerged as a natural limiting factor. Here we show that this constraint only holds in limited scenarios, and show how to overcome it using a novel method of iterated gate teleportations. This technique enables drastic reductions in the communication required for distributed quantum protocols, extending beyond the blind computation setting. Applied to blind quantum computation, this technique offers significant efficiency improvements, and in some scenarios offers an exponential reduction in communication requirements.

Figure 1

Gate teleportation procedure, derived from [15]. The top set of wires corresponds to register $R$, while the bottom set correspond to $R^{\prime }$.

Figure 2

Blind quantum computation with teleportation protocol. The dotted-line square shows the repeating pattern of operations.