Flow Ambiguity: A Path Towards Classically Driven Blind Quantum Computation
This addresses the challenge of blind quantum computation for classical users, which is incremental as it builds on existing protocols but introduces a new approach for a classical-single-server setting.
The paper tackles the problem of enabling a completely classical client to delegate quantum computations to a remote quantum server while preserving privacy, by exploiting flow ambiguity in measurement-based quantum computing to hide critical aspects of the computation.
Blind quantum computation protocols allow a user to delegate a computation to a remote quantum computer in such a way that the privacy of their computation is preserved, even from the device implementing the computation. To date, such protocols are only known for settings involving at least two quantum devices: either a user with some quantum capabilities and a remote quantum server or two or more entangled but noncommunicating servers. In this work, we take the first step towards the construction of a blind quantum computing protocol with a completely classical client and single quantum server. Specifically, we show how a classical client can exploit the ambiguity in the flow of information in measurement-based quantum computing to construct a protocol for hiding critical aspects of a computation delegated to a remote quantum computer. This ambiguity arises due to the fact that, for a fixed graph, there exist multiple choices of the input and output vertex sets that result in deterministic measurement patterns consistent with the same fixed total ordering of vertices. This allows a classical user, computing only measurement angles, to drive a measurement-based computation performed on a remote device while hiding critical aspects of the computation.