  Quantum correlations as the resource for quantum communication can be
distributed over long distances by quantum repeaters. In this Letter, we
introduce the notion of a noisy quantum repeater, and examine its role in
quantum communication. Quantum correlations shared through noisy quantum
repeaters are then characterized and their secrecy properties are studied.
Remarkably, noisy quantum repeaters naturally introduce private states in the
key distillation scenario, and consequently key distillation protocols are
demonstrated to be more tolerant.
