  We study the transmission of confidential messages across a wireless
broadcast channel with K>2 receivers and K helpers. The goal is to transmit all
messages reliably to their intended receivers while keeping them confidential
from the unintended receivers. We design a codebook based on nested lattice
structure, cooperative jamming, lattice alignment, and i.i.d. coding. Moreover,
we exploit the asymmetric compute-and-forward decoding strategy to handle
finite SNR regimes. Unlike previous alignment schemes, our achievable rates are
attainable at any finite SNR value. Also, we show that our scheme achieves the
optimal sum secure degrees of freedom of 1 for the K-receiver Gaussian
broadcast channel with K confidential messages and K helpers.
