Figure 12

Illustration of Wyner’s wiretap channel for QEPS-d encryption. The dashed box at the transmitter side represents a standard data modulation such as QPSK together with the QEPS-d encryption. The dashed box at the receiver side represents standard coherent detection together with the QEPS-d decryption. In this model, we assume the Eve also has the same standard coherent detection as Bob and knows what the data modulation is at the transmitter