Ciphertext Mapping Method based on Bitwise NOT Operation in Quantum Noise Stream Cipher

The effect of quantum noise on different bit positions of ciphertext is different in Quantum Noise Stream Cipher. This feature makes the QNSC system vulnerable to different attacks, e.g. fast correlation attack. To balance the effect of quantum noise on different bit positions, this paper proposes a ciphertext mapping method based on Bitwise NOT Operation (BNO). The performance of BNO-based 16QAM/QNSC is investigated with different intensity noises and basis states. The simulation results demonstrate that bit error rate in different bit positions of ciphertext is close to 0.5 by using BNO-based 16QAM/QNSC. In addition, the proposed method has little influence on symbol error rate of Bob.