  We introduce a device-independent two-prover scheme in which a classical
verifier is able to use a simple untrusted quantum measurement device (the
client device) to securely delegate a quantum computation to an untrusted
quantum server. To do this, we construct a parallel self-testing protocol to
perform device-independent remote state preparation of $n$ qubits and compose
this with the unconditionally secure universal verifiable blind quantum
computation (VBQC) scheme of J. F. Fitzsimons and E. Kashefi [Phys. Rev. A 96,
012303 (2017)]. Our self-test achieves a multitude of desirable properties for
the application we consider, giving rise to practical and fully
device-independent VBQC. It certifies parallel measurements of all cardinal and
intercardinal directions in the $XY$-plane as well as the computational basis,
uses few input questions (of size logarithmic in $n$ for the client and a
constant number communicated to the server), and requires only single-qubit
measurements to be performed by the client device.

Quantum Physics;Cryptography and Security