  Side-channel attacks currently constitute the main challenge for quantum key
distribution (QKD) to bridge theory with practice. So far two main approaches
have been introduced to address this problem, (full) device-independent QKD and
measurement-device-independent QKD. Here we present a third solution that might
exceed the performance and practicality of the previous two in circumventing
detector side-channel attacks, which arguably is the most hazardous part of QKD
implementations. Our proposal has, however, one main requirement: the
legitimate users of the system need to ensure that their labs do not leak any
unwanted information to the outside. The security in the low-loss regime is
guaranteed, while in the high-loss regime we already prove its robustness
against some eavesdropping strategies.
