  Motivated by the fact that coherent states may offer practical advantages it
was recently shown that a continuous-variable (CV) quantum position
verification (QPV) protocol using coherent states could be securely implemented
if and only if attackers do not pre-share any entanglement. In the
discrete-variable (DV) analogue of that protocol it was shown that modifying
how the classical input information is sent from the verifiers to the prover
leads to a favourable scaling in the resource requirements for a quantum
attack. In this work, we show that similar conclusions can be drawn for CV-QPV.
By adding extra classical information of size $n$ to a CV-QPV protocol, we show
that the protocol, which uses a coherent state and classical information,
remains secure, even if the quantum information travels arbitrarily slow,
against attackers who pre-share CV (entangled) states with a linear (in $n$)
cutoff at the photon number. We show that the protocol remains secure for
certain attenuation and excess noise.
