  With the rise of quantum technologies, data security increasingly relies on
quantum cryptography and its most notable application, quantum key distribution
(QKD). Yet, current technological limitations, in particular, the
unavailability of quantum repeaters, cause relatively low key distribution
rates in practical QKD implementations. Here, we demonstrate a remarkable
improvement in the QKD performance using end-to-end line tomography for the
wide class of relevant protocols. Our approach is based on the real-time
detection of interventions in the transmission channel, enabling an adaptive
response that modifies the QKD setup and post-processing parameters, leading,
thereby, to a substantial increase in the key distribution rates. Our findings
provide everlastingly secure efficient quantum cryptography deployment
potentially overcoming the repeaterless rate-distance limit.
