  The many-to-one interference channel has received interest by virtue of
embodying the essence of an interference network while being more tractable
than the general K-user interference channel. In this paper, we introduce
information theoretic secrecy to this model and consider the many-to-one
interference channel with confidential messages, in which each receiver, in
particular, the one subject to interference, is also one from which the
interfering users' messages need to be kept secret from. We derive the
achievable secrecy sum rate for this channel using nested lattice codes, as
well as an upper bound on the secrecy sum rate for all possible channel gain
configurations. We identify several nontrivial cases where the gap between the
upper bound and the achieved secrecy sum rate is only a function of the number
of the users K, and is uniform over all possible channel gain configurations in
each case. In addition, we identify the secure degree of freedom for this
channel and show it to be equivalent to its degree of freedom, i.e., the
secrecy in high SNR comes for free.
