Gaussian wiretap lattice codes from binary self-dual codes

We consider lattice coding over a Gaussian wiretap channel with respect to the secrecy gain, a lattice invariant introduced in [1] to characterize the confusion that a chosen lattice can cause at the eavesdropper. The secrecy gain of the best unimodular lattices constructed from binary self-dual codes in dimension n, 24 ≤ n ≤ 32 are calculated. Numerical upper bounds on the secrecy gain of unimodular lattices in general and of unimodular lattices constructed from binary self-dual codes in particular are derived for all even dimensions up to 168.