2019年12月,美国防部国防科学委员会发布《量子技术的应用》报告的摘要。摘要概述了量子传感、量子计算,以及量子通信与纠缠分发领域的主要发现,认为量子传感系统、计算及通信系统的应用将为美国防部开创量子使能能力的新时代,并就如何发展提出建议。
在关于(量子)通信系统部分,该报告摘要明确指出:理论上量子密钥分发可提供香农信息论定义的密码安全,但其能力和安全还存在欠缺,不能供美国防部使用。
该报告摘要的中文版链接地址:美国防科学委员会发布报告分析 量子技术的未来应用
为避免翻译中的歧义,特摘录有关量子通信部份的原文如下:
Quantum Information Science: Applications, Global Research and Development, and Policy Considerations
Quantum key distribution (QKD) is a method of securing communications that uses quantum physics, rather than mathematical algorithms, to safeguard data sent over unprotected networks. However, signals traveling over fiber-optic cable weaken at about 60 miles and must be retransmitted. Quantum repeaters can extend the distance the signal can be sent, but they significantly increase the complexity of the process. The communications are not only secure, but any eavesdropping attempt will destroy the communication, revealing the eavesdropping attempt.
The Chinese government has been spending heavily on QKD, but many analysts in North America and Europe do not believe that the benefits over existing nonquantum technologies outweigh the costs associated with QKD, making commercial demand difficult to ascertain.[6]
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[6]Assessment of the Future Economic Impact of Quantum Information Science, IDA.
Congressional Research Service 2
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• Finding 6: In principle, quantum key distribution (QKD) provides natural information theoretic (Shannon) cryptographic security. QKD systems do not support authenticated key exchange.
• Finding 7: QKD has not been implemented with sufficient capability or security to be deployed for DoD mission use. The Task Force concurs with the National Security Agency (NSA)’s assessment of QKD certification.
• Finding 8: QKD developments and use by foreign parties should be understood and tracked.