Robust authentication for low-power consumer devices without a keyboard remains a challenge. The recent availability of low-power neural accelerator hardware, combined with improvements in neural facial recognition algorithms provides enabling technology for low-power, on-device facial authentication. The present research work explores a number of approaches to test the robustness of a state-of-the-art facial recognition (FR) technique, Arcface for such end-to-end applications. As extreme lighting conditions and facial pose are the two more challenging scenarios for FR we focus on these. Due to the general lack of large-scale multiple-identity datasets, GAN-based re-lighting and pose techniques are used to explore the effects on FR performance. These results are further validated on the best available multi-identity datasets -MultiPIE and BIWI. The results show that FR is quite robust to pose variations up to 45-55 degrees, but the outcomes are not definitive for the tested lighting scenarios. For lighting, the tested GAN-based relighting augmentations show significant effects on FR robustness. However, the lighting scenarios from MultiPIE dataset -the best available public dataset -show some conflicting results. It is unclear if this is due to an incorrectly learned GAN relighting transformation or, alternatively, to mixed ambient/directional lighting scenes in the dataset. However, it is shown that the GAN-induced FR errors for extreme lighting conditions can be corrected by fine-tuning the FR network layers. The conclusions support the feasibility of implementing a robust authentication method for low-power consumer devices.