SaTC: CORE: Medium: Collaborative: New Directions in Public-Key and Identity-Based Encryption

公钥加密（PKE）和基于身份的加密（IBE）的发展已经彻底改变了密码学和安全通信领域。PKE允许远程方在窃听对手面前建立安全通道，并导致公钥目录存储各方的公钥。IBE的更强原语消除了对大型公钥目录的需要，尽管这是以信任中央私钥生成机构为代价的。在引入PKE和IBE几十年后，我们对这些任务的复杂性的理解，就它们可以提供什么以及构建它们所需的棘手假设而言，仍然非常有限。在高层次上，该项目的目标是在这些方面取得进展。该项目的新颖之处包括研究新的加密工具，这些工具可以充分利用IBE和PKE，以及开发基于最佳棘手假设的IBE和PKE的新技术。该项目的影响是通过新的方式来确保通信。此外，研究人员之间的合作将有助于提高两个研究所的研究生的教育。更具体地说，本项目的目标是在两个方向上追求：（1）从最小假设的增强和（2）识别障碍和证明下限。该项目的第一个方向侧重于从最小的假设中获得IBE和PKE的增强安全性。如果没有对何时达到最佳结果的正式理解，上述关于从最小假设设计结构的努力将是不完整的。本项目的第二个主要组成部分侧重于确定这些最低限度的假设。具体而言，该项目的目标是证明黑箱和非黑箱障碍和（效率）下限，补充在第一个方向证明的结果。该奖项反映了NSF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。

Developments in public-key encryption (PKE) and identity-based encryption (IBE) have revolutionized the field of cryptography and secure communication in general. PKE allowed remote parties to establish secure channels in front of eavesdropping adversaries, and led to public-key directories storing parties' public-keys. The stronger primitive of IBE eliminated the need for a large public-key directory, though this comes at the cost of trusting a central private-key generation authority. Decades after introduction of PKE and IBE, our understanding of the complexity of these tasks, in terms of what they can offer and the intractability assumptions needed for building them, is still very limited. At a high level, the goal of the project is to make progress exactly on these fronts. The project's novelties include a study of new cryptographic tools that give best of both IBE and PKE as well as developing new techniques for basing IBE and PKE on optimal intractability assumptions. The project impact is through new ways to secure communication. In addition, the collaboration between the investigators will help enhance the education of the graduate students at both institutes.More specifically, the goals of this project are pursued in two directions: (1) enhancements from minimal assumptions and (2) identifying barriers and proving lower bounds. The first direction of the project focuses on obtaining enhanced security for IBE and PKE from minimal assumptions. The efforts above on designing constructions from minimal assumptions would not be complete without having a formal understanding about when we have achieved optimal results. The second principal component of this project focuses on identifying those minimal assumptions. Specifically, the project's goal is to prove black-box and non-black-box barriers and (efficiency) lower bounds, complementing the results proved in the first direction.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.