Zhao Wei, Shi Ronghua, Huang Duan
School of Computer Science and Engineering, Central South University, Changsha, 410083, China.
Sci Rep. 2019 Dec 3;9(1):18155. doi: 10.1038/s41598-019-54249-0.
By manipulating the reference pulses amplitude, a security vulnerability is caused by self-reference continuous-variable quantum key distribution. In this paper, we formalize an attack strategy for reference pulses, showing that the proposed attack can compromise the practical security of CVQKD protocol. In this scheme, before the beam splitter attack, Eve intercepts the reference pulses emitted by Alice, using Bayesian algorithm to estimate phase shifts. Subsequently, other reference pulses are re-prepared and resubmitted to Bob. In simulations, Bayesian algorithm effectively estimates the phase drifts and has the high robustness to noise. Therefore, the eavesdropper can bias the excess noise due to the intercept-resend attack and the beam splitter attack. And Alice and Bob believe that their excess noise is below the null key threshold and can still share a secret key. Consequently, the proposed attack shows that its practical security can be compromised by transmitting the reference pulses in the continuous-variable quantum key distribution protocol.
通过操纵参考脉冲的幅度，自参考连续变量量子密钥分发会导致安全漏洞。在本文中，我们形式化了一种针对参考脉冲的攻击策略，表明所提出的攻击能够危及连续变量量子密钥分发（CVQKD）协议的实际安全性。在该方案中，在分束器攻击之前，伊芙（Eve）拦截爱丽丝（Alice）发射的参考脉冲，使用贝叶斯算法估计相移。随后，重新制备其他参考脉冲并重新发送给鲍勃（Bob）。在模拟中，贝叶斯算法有效地估计了相位漂移，并且对噪声具有高鲁棒性。因此，窃听者可以通过拦截重发攻击和分束器攻击使过量噪声产生偏差。而且爱丽丝和鲍勃认为他们的过量噪声低于零密钥阈值并且仍然可以共享一个秘密密钥。因此，所提出的攻击表明，在连续变量量子密钥分发协议中传输参考脉冲会危及其实用安全性。
