  In this work we explore the security of secret keys generated via the
electromagnetic reciprocity of the wireless fading channel. Identifying a new
sophisticated colluding attack, we explore the information-theoretic-security
for such keys in the presence of an all-powerful adversary constrained only by
the laws of quantum mechanics. Specifically, we calculate the reduction in the
conditional mutual information between transmitter and receiver that can occur
when an adversary with unlimited computational and communication resources
places directional antenna interceptors at chosen locations. Such locations, in
principal, can be arbitrarily far from the intended receiver yet still
influence the secret key rate.
