  Quantum key distribution performs the trick of growing a secret key in two
distant places connected by a quantum channel. The main reason is that the
legitimate users can bound the information gathered by the eavesdropper. In
practical systems, whether because of finite resources or external conditions,
the quantum channel is subject to fluctuations. A rate adaptive information
reconciliation protocol, that adapts to the changes in the communication
channel, is then required to minimize the leakage of information in the
classical postprocessing.
  We consider here the leakage of a rate-adaptive information reconciliation
protocol. The length of the exchanged messages is larger than that of an
optimal protocol; however, we prove that the min-entropy reduction is limited.
The simulation results, both on the asymptotic and in the finite-length regime,
show that this protocol allows to increase the amount of distillable secret
key.
