TWC: Small: On the Design of Secure Hash Functions and Block Ciphers

该项目通过研究基于更坚实的理论基础的新型结构，重新审视了构建安全散列函数，分组密码和各种重要的密码原语的基本设计原理，但仍然足够有效地用于实际应用。特别是，该项目的重点是分析和改进使用散列函数和分组密码作为消息发送器，密钥导出函数，消息认证码，流密码，承诺方案和随机预言机。此外，研究人员还研究了新的操作模式，以从更简单的固定长度组件（如分组密码和固定长度压缩函数）构建复杂的可变长度原语。该项目还研究了可证明免疫加密算法和标准对潜在未知后门的可行性。最后，该项目为分析理想安全模型（如随机预言机模型和理想密码模型）下的密码方案奠定了坚实的基础。该项目旨在产生更安全的散列函数和分组密码，以及在重要的密码应用中更安全和/或有效地使用散列函数和分组密码。除了推进密码学理论之外，该项目还通过建议更合理地使用各种加密构建块来影响安全系统的实际设计。PI定期教授密码学和网络安全课程，并积极将新成果融入他所教授的课程中。 此外，该提案还有一个重要的研究生和博士后培训部分。

This project revisits the basic design principle for constructing secure hash functions, block ciphers, and various important cryptographic primitives which are built from them, by investigating new types of constructions that are based on firmer theoretical foundations, and yet are still efficient enough for practical use. In particular, the project focuses on analyzing and improving the use of hash functions and block ciphers as message digests, key derivation functions, message authentication codes, stream ciphers, commitment schemes and random oracles. Additionally, the investigators study novel modes of operation to build complex variable-length primitives from simpler, fixed length components, such as block ciphers and fixed-length compression functions. The project also examines the feasibility of provably immunizing cryptographic algorithms and standards against potentially unknown backdoors. Finally, the project builds firmer foundations for analyzing cryptographic schemes in the idealized security models, such as the random oracle and the ideal cipher models. The project aims to yield more secure hash functions and block ciphers, and more secure and/or efficient usage of hash functions and block ciphers in important cryptographic applications. Besides advancing the theory of cryptography, this project also impacts the real-world design of secure systems, by suggesting more sound use of various cryptographic building blocks for such applications. The PI regularly teaches courses in cryptography and network security, and is actively incorporating the new results into the courses he teaches. In addition, the proposal has a significant graduate student and postdoc training component.