Evaluating Quantum Circuit Protection Methods After Compilation: An Empirical Comparison

arXiv:2611.14919v1 Announce Type: new Abstract: Quantum cloud providers can read the circuits they receive and their outputs, yet methods for hiding a circuit are usually evaluated on the circuit as written, before compilation optimises it. We compare three ObfusQate schemes (inverse, composite and delayed gates), ECQCO and Q-MaskCut under one protocol that compiles every protected circuit at optimisation level 3 before measuring it; the goal is to keep the provider from learning the user's algorithm and answer. Q-MaskCut is one example combination of existing techniques: a one-time-pad key, decoy wires, circuit cutting with a random rotation pair across each cut, and Pauli twirling with dynamical-decoupling masking after compilation.