可调分组密码设计理论的若干关键问题研究

As an important part within the infrastructure of information and network security, block cipher always serves as the core cryptographic algorithm in realizing the functionalities of data encryption, message authentication and key management, and has been widely applied in online payment, mobile communication, remote control, email, etc. Once practically implemented block ciphers have some security flaw, it would cause serious damage to the society. Thus the design theory of block cipher is always an important research direction in the field of modern cryptography. Recently a new type of block cipher, tweakable block cipher, attracts more and more attentions, because it is better suited for building security protocol. Hence it is quite possible that tweakable block cipher will replace classical block cipher in future. This project focuses on several important topics of the design theory of tweakable block cipher, digs the essential bottleneck of current theory, considers potential solutions, proposes new design idea, and finally builds new tweakable block ciphers that achieve better security and efficiency. This research will enrich and improve the design theory of tweakable block cipher, and advance theory of cryptography. Meanwhile, it will facilitate the standardization of tweakable block cipher in China.

分组密码是信息与网络安全中实现数据加密、消息鉴别认证及密钥管理的核心机制，广泛应用于网上支付、移动通信、远程控制、电子邮件等。一旦实际应用的分组密码算法存在着安全缺陷的话，这将给社会带来严重的危害。因此分组密码的设计理论一直是现代密码学的重要研究方向。近年来，一种新型分组密码：可调分组密码，因其更加适合于构造安全协议的优势，受到了越来越多的重视，呈现出在将来取代传统分组密码的趋势和可能性。本项目针对可调分组密码设计理论面临的若干热点和难点问题，深入挖掘当前理论的内在瓶颈，积极探索解决方案，提出新的设计思想和方法，最终设计新的可调分组密码算法，提升安全和效率等性能。相关研究将进一步丰富和完善可调分组密码算法的设计理论，推动密码学发展。同时，也对我国可调分组密码算法的自主设计、开发与标准化起到促进和推动作用。

可调分组密码更加适合于构造安全协议的优势，受到了越来越多的重视，有潜力应用于网上支付、移动通信、远程控制、电子邮件等。本项目针对可调分组密码设计理论面临的若干热点和难点问题，深入挖掘当前理论的内在瓶颈，积极探索解决方案，提出新的设计思想和方法，最终设计新的可调分组密码算法，提升安全和效率等性能。相关研究将进一步丰富和完善可调分组密码算法的设计理论，推动密码学发展。同时，也对我国可调分组密码算法的自主设计、开发与标准化起到促进和推动作用。我们提出了32个最优安全的可调分组密码算法；单一密钥的基于可调分组密码的加密保长协议；基于广义Feistel的可调分组密码设计理论改进；可调分组密码的不可预知安全性；可调分组密码底层组件KAF的简约结构；底层组件的抗量子攻击安全性；刷新了经典哈希组合器的安全性边界；公开置换Keccak-f的改进零和区分器；单一密钥的PRP-to-PRF结构； 国际标准ISO/IEC 9797-1的安全漏洞等。