  Unambiguous identification of Majorana physics presents an outstanding
problem whose solution could render topological quantum computing feasible. We
develop a numerical approach to treat finite-size superconducting chains
supporting Majorana fermions, which is based on iterative application of a
two-site Bogoliubov transformation. We demonstrate the applicability of the
method by studying a resonant level attached to the superconductor subject to
external perturbations. In the topological phase, we show that the spectrum of
a single resonant level allows to distinguish peak coming from Majorana physics
from the Kondo resonance.
