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

该项目旨在通过使秘密密钥和/或通信变得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，以确保它无法存储足够的信息来破坏计划，即使提供的资源比诚实的用户多得多。该项目的新颖性是新的密码系统，其中：(1)即使对手破坏了存储秘密密钥的机器并泄露了大量数据，安全性仍然有效；(2)安全性不依赖于任何未经证实的数学假设，而只需要一个大密钥，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，重点培养多样性。加密方案和协议的设计传统上努力使密钥和通信尽可能小。在这个项目中，研究人员认为，在几个重要的设置中，可以通过使密钥和/或通信变得更大来显著提高安全性，同时仍然允许所产生的方案非常实用。该项目的重点是三个这样的背景。第一个设置考虑通过直接窃取相应密钥来破坏加密方案的对手。缓解此类攻击的一个有希望的方法是故意使加密密钥变得很大，以防止对手完整地泄露它们。该项目提出了新的研究方向，使这些计划更接近现实。第二种设置研究具有信息论(IT)安全性的密码系统，即使是针对具有无限计算能力的攻击者，这些密码系统也可以被证明是安全的。虽然众所周知，这样的密码系统需要一个大密钥，但该项目研究如何通过确保它们是无状态的，并在每次使用时只读取其大密钥的一小部分来使其实用。第三个设置研究IT安全协议，其中协议通信被故意设置得很大，因此攻击者无法将其全部存储。诚实的参与者使用比对手少得多的存储空间以流方式处理通信。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.