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Side-channel attacks allow an Eavesdropper to use insecurities in the practical implementation of QKD systems to gain an advantage that is not considered by security proofs that assume perfect implementations. In this work we specify a side-channel capability for Eve that has yet to be considered, before then going on to discuss a scheme to autonomously detect such an attack during an ongoing QKD session, and the limits as to how fast a detection can be made. The side-channel capability is very general and covers a wide variety of possible implementations for the attack itself. We present how Alice and Bob can put in place a countermeasure to continue use of the QKD system, once a detection is made, regardless of the ongoing side-channel attack. This prevents downtime of QKD systems, which in critical infrastructure could pose severe risks. We then extend Eves side-channel capability and present a modified attack strategy. This strengthened attack can be detected under certain conditions by our scheme, however intelligent choices of parameters from Eve allow her strengthened attack to go undetected. From this, we discuss the implications this has on Privacy Amplification, and therefore on the security of QKD as a whole. Finally, consideration is given as to how these types of attacks are analogous to certain types of faults in the QKD system, how our detection scheme can also detect these faults, and therefore how this adds autonomous fault detection and redundancy to implementations of QKD., Comment: 8 pages, 5 figures, to be submitted to Physical Review A

The third-generation South Pole Telescope camera is designed to measure the cosmic microwave background across three frequency bands (95, 150 and 220 GHz) with ~16,000 transition-edge sensor (TES) bolometers. Each multichroic pixel on a detector wafer has a broadband sinuous antenna that couples power to six TESs, one for each of the three observing bands and both polarization directions, via lumped element filters. Ten detector wafers populate the focal plane, which is coupled to the sky via a large-aperture optical system. Here we present the frequency band characterization with Fourier transform spectroscopy, measurements of optical time constants, beam properties, and optical and polarization efficiencies of the focal plane. The detectors have frequency bands consistent with our simulations, and have high average optical efficiency which is 86%, 77% and 66% for the 95, 150 and 220 GHz detectors. The time constants of the detectors are mostly between 0.5 ms and 5 ms. The beam is round with the correct size, and the polarization efficiency is more than 90% for most of the bolometers, Comment: Conference proceeding for Low Temperature Detectors 2017