  A recent line of work on lattice codes for Gaussian wiretap channels
introduced a new lattice invariant called secrecy gain as a code design
criterion which captures the confusion that lattice coding produces at an
eavesdropper. Following up the study of unimodular lattice wiretap codes [1],
this paper investigates 2- and 3-modular lattices and compares them with
unimodular lattices. Most even 2- and 3-modular lattices are found to have
better performance, that is, a higher secrecy gain than the best unimodular
lattices in dimension n, n is between 2 and 23. Odd 2-modular lattices are
considered, too, and three lattices are found to outperform the best unimodular
lattices.
