We suggest a self-testing teleportation configuration for photon q-bits based on a Mach-Zehnder interferometer. That is, Bob can tell how well the input state has been teleported without knowing what that input state was. One could imagine building a "locked" teleporter based on this configuration. The analysis is performed for continuous variable teleportation but the arrangement could equally be applied to discrete manipulations.
@article{arxiv.quant-ph/9906072,
title = {The Mach-Zehnder and the Teleporter},
author = {T. C. Ralph},
journal= {arXiv preprint arXiv:quant-ph/9906072},
year = {2008}
}