  Blind quantum computation is a novel secure quantum-computing protocol that
enables Alice, who does not have sufficient quantum technology at her disposal,
to delegate her quantum computation to Bob, who has a fully fledged quantum
computer, in such a way that Bob cannot learn anything about Alice's input,
output and algorithm. A recent proof-of-principle experiment demonstrating
blind quantum computation in an optical system has raised new challenges
regarding the scalability of blind quantum computation in realistic noisy
conditions. Here we show that fault-tolerant blind quantum computation is
possible in a topologically protected manner using the
Raussendorf-Harrington-Goyal scheme. The error threshold of our scheme is
0.0043, which is comparable to that (0.0075) of non-blind topological quantum
computation. As the error per gate of the order 0.001 was already achieved in
some experimental systems, our result implies that secure cloud quantum
computation is within reach.

Quantum Physics