  Alice is transmitting a private message to Bob across a bosonic wiretap
channel with the help of a public feedback channel to which all parties,
including the fully-quantum equipped Eve, have completely noiseless access. We
find that by altering the model such that Eve's copy of the initial round of
feedback is corrupted by an iota of noise, one step towards physical relevance,
the capacity can be increased dramatically. It is known that the private
capacity with respect to the original model for a pure-loss bosonic channel is
at most $- \log(1-\eta)$ bits per mode, where $\eta$ is the transmissivity, in
the limit of infinite input photon number. This is a very pessimistic result as
there is a finite rate limit even with an arbitrarily large number of input
photons. We refer to this as a loss limited rate. However, in our altered model
we find that we can achieve a rate of $(1/2) \log(1 + 4 \eta N_S)$ bits per
mode, where $N_S$ is the input photon number. This rate diverges with $N_S$, in
sharp contrast to the result for the original model. This suggests that
physical considerations behind the eavesdropping model should be taken more
seriously, as they can create strong dependencies of the achievable rates on
the model. For by a seemingly inconsequential weakening of Eve, we obtain a
loss-unlimited rate. Our protocol also works verbatim for arbitrary i.i.d.
noise (not even necessarily Gaussian) injected by Eve in every round, and even
if Eve is given access to copies of the initial transmission and noise. The
error probability of the protocol decays super-exponentially with the
blocklength.
