On the Symmetric 2-User Deterministic Interference Channel with Confidential Messages

We consider 2-user symmetric interference channels with confidential messages. For the linear deterministic model of this channel, we develop inner and outer bounds for the symmetric secure rate, which are shown to match and characterize the symmetric secure capacity for a wide range of channel parameters. For the achievability, we present a cooperative jamming scheme based on interference alignment principle, which is optimal for all regimes where the symmetric secure capacity is established. For the converse, a tighter outer bound than all previously existing ones is provided for the regime where the symmetric secure capacity is still open.