Gaussian wiretap channel with collaborative wiretappers

In this paper, we consider the compound wiretap channel with collaborative wiretappers. Contrarily to [1], where the wiretappers act independently, we analyze the setup when the wiretappers form a coalition, which shares the observed data within the coalition. The goal of coalition consists in learning the secret message communicated to the legitimate user by sharing their observations to produce the best possible estimate thus benefiting from available redundancy. We analyze the secrecy capacity for the Gaussian data and correlated observations. As the result, we provide the estimate of the impact of coalition of wiretappers on reduction of secrecy capacity.