  Continuous-variable quantum key distribution employs the quadratures of a
bosonic mode to establish a secret key between two remote parties. The
resulting secret-key rate depends not only on the loss and noise in the
communication channel, but also on a series of data-processing steps that are
needed for transforming shared correlations into a final string of secret bits.
Within the general setting of composable finite-size security, we consider a
coherent-state protocol, whose quantum communication is simulated and classical
data is post-processed via procedures of parameter estimation, error correction
and privacy amplification. Such steps are presented in detail and suitably
adapted to follow recently-developed tools for composable security analysis.
For this advanced approach on data-processing, we provide a Python-based
environment that allows us to investigate and optimize the protocol parameters
to be used in practical experimental implementations.
