Quantify the Success Probability of Honest-But-Curious Relay Attack for Modulation Based Physical Layer Network Coding

Physical layer network coding (PNC) has been considered a valid way to improve transmission efficiency, especially in the distributed network. Furthermore, due to the received signal at the relay is a superposed codeword that cannot be decomposed to recover the individual information, PNC is also viewed as a promising approach for physical layer security. In this paper, we reveal that information leakage risk exists for the honest-but-curious relay. Under such an attack, the honest-but-curious relay tries to recover the information from both transmitting sides while complying with the transmission protocol honestly. Then, we quantify the success probability of the honest-but-curious relay attack for modulation-based PNC. To the best of our knowledge, such a formulation is the first numerical formulation. We analyzed the BPSK, QPSK, and 16-QAM respectively, then we formulate the general attack successful probability for M-QAM. With the information-theoretic analysis results, it has been clearly shown that the attack successful probability is decreased with the increasing modulation order. Finally, the simulation is performed to demonstrate the theoretical analysis.