CT-ISG: Foundations of Position Based Cryptography

翻译后摘要：本研究考虑的问题是什么构成的身份密码学。典型 身份的例子包括个人的姓名和社会安全号码，或指纹/虹膜扫描， 或地址，或来自某个可信公钥基础设施的（未撤销的）公钥。在 然而，在许多情况下，一个人所处的位置决定了他或她的身份。比如说， 我们知道一个银行出纳员在防弹银行窗口后面的角色，不是因为他向我们展示了他的 只需要知道他的位置这项研究关注的一个问题是， 问题是：是否有可能让设备的“地理位置”参与 正在定义此设备具有的凭据集？在什么方面有什么新的可能性 能在这种情况下实现吗？首先，本研究探讨了在这种情况下的中心任务， 也就是说，安全地验证设备的位置。尽管在这方面做了大量工作，我们的初步 发现显示在“香草”（即，标准）模型，上述安全定位任务是 不可能实现。 本研究着重于一个不同的模型：研究有界存储中的位置证明 模型（即我们假设对手的总记忆有一定的界限）。在这种情况下， 本研究旨在实现各种任务，包括安全定位、基于位置的密钥交换和更一般的基于位置的安全功能。这个项目的更广泛的影响是，首先确定以前尝试中的各种缺陷;第二，提出一个新的框架，实际上可以进行严格的证明;第三，通过将其置于坚实的理论基础上，为进一步研究打开这个重要的研究领域。该项目的总体目标是开发一种基于位置的密码学的原则性方法，定义关键问题，并建立可证明安全的不可能结果和新框架。

Abstract: This research considers the question of what constitutes identities in cryptography. Typical examples of identities include a person's name and social-security number, or fingerprint/iris-scan, or address, or a (non-revoked) Public-Key coming from some trusted public-key infrastructure. In many situations, however, where the person is located defines his or her identity. For example, we know the role of a bank-teller behind a bullet-proof bank window not because he shows us his credentials but by merely knowing his location. One of the questions that this research focuses on is the following: is it possible to have the "geographical position" of a device take part in defining the set of credentials this device has? What are the new possibilities in terms of what can be achieved in this setting? First, this research examines the central task in this setting, i.e., securely verifying the position of a device. Despite much work in this area, our preliminary findings show that in the "vanilla" (i.e., standard) model, the above task of secure positioning is impossible to achieve. This research focuses on a different model: to study the proof of position in the bounded storage model (i.e. where we assume some bound on the total memory of the adversary). In this setting, this research aims to achieve various tasks including secure positioning, position-based key exchange, and more general position-based secure functionalities. The broader impact of this project is to first identify various flaws in previous attempts; second, to propose a new framework where rigorous proofs are in fact possible; third, to open this important area of research for further study by putting it on solid theoretical foundations. The overall aim of this project is to develop a principled approach to position-based cryptography, to define key problems, and to establish both impossibility results and new frameworks that are provably secure.