Collaborative Research: SaTC: CORE: Medium: Making Crypto Too BIG To Break

该项目旨在通过使密钥和/或通信更大来构建具有强大安全保证的新密码系统。统一的技术是用信息压倒对手，以确保它不能存储足够的信息来破坏方案，即使提供比诚实用户多得多的资源。该项目的新奇之处在于新的密码系统：(1)即使攻击者破坏了存储密钥的机器并泄露了大量数据，安全性仍然保持不变；(2)安全性不依赖于任何未经证明的数学假设，而是只需要一个大密钥，或者诚实参与者之间的大量通信。该项目的影响是：(a)在现实世界中设计更安全的系统，(b)从计算机科学的许多不同领域中协同、统一和抽象技术，以及(c)指导本科生、研究生和博士后，重点是促进多样性。传统上，加密方案和协议的设计力求使密钥和通信尽可能小。在这个项目中，研究人员认为，有几个重要的设置可以通过使密钥和/或通信更大来显着提高安全性，同时仍然允许最终方案非常实用。该项目侧重于三个这样的设置。第一个设置考虑一个对手通过直接窃取相应的密钥来破坏加密方案。缓解此类攻击的一种有希望的方法是故意使加密密钥非常大，以防止对手将其全部泄露。这个项目为使这些方案更接近现实提出了新的研究方向。第二组研究具有信息理论（IT）安全性的密码系统，即使面对具有无限计算能力的攻击者，它也可以证明是安全的。虽然已知这样的密码系统需要一个大密钥，但该项目研究了如何通过确保它们是无状态的，并且在每次使用时仅读取其大密钥的一小部分来使它们变得实用。第三种设置研究it安全协议，其中协议通信故意变大，使攻击者无法存储所有信息。诚实的参与者以流方式处理通信，使用比对手少得多的存储空间。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project aims to build new cryptosystems with strong security guarantees, by making the secret keys and/or communication large. The unifying technique is to overwhelm the adversary with information to ensure that it cannot store enough of it to break the scheme, even given significantly more resources than the honest users. The project's novelties are new cryptosystems where: (1) security holds even if an adversary compromises the machine storing the secret key and exfiltrates large amounts of data, (2) security does not rely on any unproven mathematical assumptions, but instead just requires either a large key, or large amounts of communication between the honest participants. The project's impacts are: (a) the design of more secure systems in the real world, (b) synergizing, unifying and abstracting techniques from many diverse areas of computer science, and (c) mentoring undergraduates, graduate students and postdocs with an emphasis on fostering diversity.The design of cryptographic schemes and protocols traditionally strives to make secret keys and communication as small as possible. In this project, the investigators argue that there are several important settings where it is possible to dramatically improve security by making secret keys and/or communication large, while still allowing the resulting scheme to be quite practical. The project focuses on three such settings. The first setting considers an adversary who breaks a cryptographic scheme by outright stealing the corresponding secret key. A promising approach to mitigate against such attacks is to make cryptographic keys intentionally huge, to prevent an adversary from exfiltrating them in their entirety. This project suggests novel research directions towards bringing such schemes closer to reality. The second setting studies cryptosystems with Information-theoretic (IT) security, that are provably secure even against attackers with unlimited computational power. While such cryptosystems are known to require a large key, the project studies how to make them practical by ensuring that they are stateless and read only small portions of their large keys at every use. The third setting studies IT-secure protocols, where the protocol communication is made intentionally large, so that it becomes infeasible for the attacker to store it all. The honest participants process the communication in a streaming manner using much less storage than the adversary.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.