When the technology to build quantum computers finally becomes
available, it is highly likely that it will only be accessible to a handful of
centres around the world. Much like today's rental system of
supercomputers, users will probably be granted access to the computers in a limited way. This begs the question: how will the users interface with the quantum computer?
We present the first protocol which allows Alice to have Bob carry out a
quantum computation for her such that Alice's inputs, outputs and
computation remain perfectly private, and where Alice does not require
any quantum computational power or memory. Our protocol is interactive and from Alice's point of view, can be implemented with physical systems that are already available and well-developed.