Secrecy and reliable Byzantine detection in a Gaussian untrusted two-hop link

We consider a Gaussian two-hop link where the source and the destination can communicate only via a relay node who is both an eavesdropper and a Byzantine attacker. Both the source and the destination have transmission capability, and the relay node receives a superposition of their transmitted signals plus noise. The proposed coding scheme ensures that the probability of an undetected Byzantine attack decreases exponentially fast with respect to the number of channel uses N_T while the loss in the secrecy rate can be made arbitrarily small. This improves our previous result where this probability only decreased exponentially with respect to √(N_T).