Huang Chaoran, Ma Philip Y, Blow Eric C, Mittal Prateek, Prucnal Paul R
Opt Express. 2019 Oct 28;27(22):32096-32110. doi: 10.1364/OE.27.032096.
We propose and experimentally demonstrate an approach to generate and distribute secret keys over optical fiber communication infrastructure. Mach-Zehnder interferometers (MZIs) are adopted for key generation by transferring the environmental noise to random optical signals. A novel combination of wideband optical noise and an asymmetric MZI structure enables the secret keys to be securely transmitted and exchanged over public fiber links without being detected. We experimentally demonstrate this system and show reliable performance: keys are generated at the rate of 502 bit/s, and are successfully exchanged between two parties over a 10 km optical fiber with a bit error of ∼ 0.3%. System security analysis is performed by corroborating our experimental findings with simulations. The results show that our system can protect the key distribution under different attacks, attributed to wideband optical noise and asymmetric MZI structures. Compared to the previous schemes based on distributed MZIs, our scheme exploits localized MZI which provides twofold advantages. Firstly, the key generation rate can be increased by a factor of 5.7 at a negligible additional cost. Secondly, the system becomes robust to, in particular, active intrusion attack. The proposed system is a reliable and cost-effective solution for key establishment, and is compatible with the existing optical fiber communication infrastructure.
我们提出并通过实验证明了一种在光纤通信基础设施上生成和分发密钥的方法。采用马赫-曾德尔干涉仪（MZIs）通过将环境噪声转换为随机光信号来生成密钥。宽带光噪声和非对称MZI结构的新颖组合使得密钥能够在公共光纤链路上安全地传输和交换而不被检测到。我们通过实验演示了该系统并展示了可靠的性能：密钥以502比特/秒的速率生成，并在10公里的光纤上在双方之间成功交换，误码率约为0.3%。通过将我们的实验结果与模拟结果进行对比来进行系统安全性分析。结果表明，由于宽带光噪声和非对称MZI结构，我们的系统能够在不同攻击下保护密钥分发。与先前基于分布式MZIs的方案相比，我们的方案采用了局部MZI，具有双重优势。首先，密钥生成速率可以在可忽略不计的额外成本下提高5.7倍。其次，该系统对主动入侵攻击尤其具有鲁棒性。所提出的系统是一种可靠且经济高效的密钥建立解决方案，并且与现有的光纤通信基础设施兼容。
