Among physical layer encryption schemes,the quantum noise stream cipher(QNSC)has garnered significant attention due to its compatibility with high-speed commercial fiber-optic communication systems.After careful analy...Among physical layer encryption schemes,the quantum noise stream cipher(QNSC)has garnered significant attention due to its compatibility with high-speed commercial fiber-optic communication systems.After careful analysis of the encryption scheme,we reveal that QNSC transmission systems exhibit a security vulnerability in their encoding scheme.This vulnerability limits quantum noise to alerting high-order information bits in plaintext-dependent regions,creating structured ciphertext concealment.Numerical simulation and experimental verification both indicate that an eavesdropper can use quantization-attack to crack this vulnerability.Existing security assessment methods will overestimate the system's security under quantization-attack.In addition,system security demonstrates a strong linear dependence on the plaintext modulation format,rather than the ciphertext modulation format as is widely presumed.To further enhance system security,the probability distribution is further introduced into the encoding process of ciphertext.The experiment results show that we not only achieved random concealment of ciphertext by quantum noise but also enhanced the eavesdropper's symbol error rate by~86%and maximally expanded the key space of the QAM-QNSC system by 2^(27.2).展开更多
基金National Natural Science Foundation of China(62431024,62575248,U22A2089)Key Technology Research and Development Program of Shandong Province(2023CXPT100)Outstanding Young Scientist Fund of Sichuan Provincial Natural Science Foundation(2025NSFJQ0052)。
文摘Among physical layer encryption schemes,the quantum noise stream cipher(QNSC)has garnered significant attention due to its compatibility with high-speed commercial fiber-optic communication systems.After careful analysis of the encryption scheme,we reveal that QNSC transmission systems exhibit a security vulnerability in their encoding scheme.This vulnerability limits quantum noise to alerting high-order information bits in plaintext-dependent regions,creating structured ciphertext concealment.Numerical simulation and experimental verification both indicate that an eavesdropper can use quantization-attack to crack this vulnerability.Existing security assessment methods will overestimate the system's security under quantization-attack.In addition,system security demonstrates a strong linear dependence on the plaintext modulation format,rather than the ciphertext modulation format as is widely presumed.To further enhance system security,the probability distribution is further introduced into the encoding process of ciphertext.The experiment results show that we not only achieved random concealment of ciphertext by quantum noise but also enhanced the eavesdropper's symbol error rate by~86%and maximally expanded the key space of the QAM-QNSC system by 2^(27.2).
