On the Foundations and Methods of Quantum Cryptography

论量子密码学的基础和方法

• 批准号: RGPIN-2015-05385
• 负责人: Salvail, Louis
• 金额: $ 2.11万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613520
• 关键词: Foundations; Methods; Quantum; Cryptography

This project aims at improving our understanding of the foundations of quantum cryptography, to develop quantum tools allowing for new cryptographic primitives and a better understanding of its limits. The fact that two parties can agree upon a secret key using quantum communication (i.e. quantum key distribution) has first given hopes that the main goals of cryptography: data privacy, data authenticity, and data integrity could be provided information theoretically by quantum mechanics while, as we know, being impossible by classical means alone. Even before the security of quantum key distribution was fully established, researchers have shown that other cryptographic primitives would remain impossible even by all powerful quantum experimentalists. The picture of cryptography in a quantum world is therefore not as unconstrained as one could have first thought. In addition to the realization of classical cryptographic tasks by quantum information processing, quantum cryptography is also interested in providing means by which cryptographic techniques can be applied to quantum systems. Very often, classical primitives have a natural quantum interpretation. For instance, signing documents in order to publicly guarantee their integrity and authenticity has a natural quantum counterpart: signing quantum states. Quantum cryptography is interested in determining under what conditions, if any, these quantum primitives are possible. As an example, although signing documents can be performed securely based upon reasonable computational assumptions, signing quantum states remains impossible in this setting. On the other hand, while electronic money cannot be easily protected against double-spending, quantum money does not have this vulnerability, thanks to the uncertainty principle.    During the last fifteen years or so, research in quantum information theory has improved a great deal our understanding of the cryptographic power and limits of quantum mechanics. One thing is clear, the quantum cryptographic landscape is very different from its classical counterpart and its outlines are still not very well understood. The anticipated outcomes of this program include a better understanding of what is possible and at what cost, new primitives that can be implemented in practice and that provide satisfactory security guarantees, and information theoretical tools allowing to shed new lights on the foundations of quantum cryptography. The program will contribute in a better understanding of how classical and quantum methods can be used together to improve cryptographic constructs for the digital age, at the outset of the quantum age.

该项目旨在提高我们对量子密码学基础的理解，开发允许新的密码原语的量子工具，并更好地了解其局限性。双方可以使用量子通信（即量子密钥分配）就密钥达成一致的事实首先给了人们希望，密码学的主要目标：数据隐私，数据真实性和数据完整性可以通过量子力学理论上提供信息，而我们知道，仅通过经典手段是不可能的。甚至在量子密钥分配的安全性完全建立之前，研究人员已经证明，即使是所有强大的量子实验学家，其他密码原语也是不可能的。因此，量子世界中密码学的图景并不像人们最初想象的那样不受约束。除了通过量子信息处理实现经典密码任务之外，量子密码学还对提供密码技术可以应用于量子系统的手段感兴趣。通常，经典基元具有自然的量子解释。例如，为了公开保证文件的完整性和真实性而对文件进行签名有一个自然的量子对应物：对量子态进行签名。量子密码学感兴趣的是确定在什么条件下，如果有的话，这些量子原语是可能的。例如，尽管可以基于合理的计算假设安全地执行签名文档，但在这种设置中签名量子态仍然是不可能的。另一方面，虽然电子货币不能轻易地防止双重支出，但量子货币没有这种脆弱性，这要归功于不确定性原理。   在过去15年左右的时间里，量子信息理论的研究极大地提高了我们对量子力学的密码能力和局限性的理解。有一件事是清楚的，量子密码学的前景与经典密码学有很大的不同，它的轮廓仍然没有得到很好的理解。这个计划的预期成果包括更好地理解什么是可能的，以什么样的代价，可以在实践中实现的新原语，并提供令人满意的安全保证，和信息理论工具，允许对量子密码学的基础进行新的阐述。该计划将有助于更好地理解经典和量子方法如何在量子时代开始时一起使用，以改善数字时代的密码结构。