有损陷门函数及变体的构造与应用研究

复杂的网络环境（如多方通信环境、侧信道信息泄漏环境）对加密方案的安全性提出了新的更高挑战，因此，必须寻找新的工具，在新的安全模型下对公钥加密方案进行设计。有损陷门函数是近年来提出的新颖重要的密码学原型，是应对上述挑战的重要工具。本项目将对有损陷门函数及变体的构造与应用展开深入研究，具体包括：(1)新的更有效的基于通用假设或基于不同具体假设的有损陷门函数的构造方法和途径；(2)有损陷门函数在构造高安全加密方案中的应用。研究利用有损陷门函数等相关工具构造更有效的或在更强安全模型下的选择密文攻击安全、选择打开攻击安全和抗泄露的公钥加密和基于ID的加密方案；(3)有损陷门函数变体的构造和新应用。从实际应用需求出发，设计具有变色龙、匿名性、非延展性、可更新等特性的有损陷门函数以及基于ID的有损陷门函数。本项目的研究将解决有损陷门函数构造和应用中的多个重要问题，对复杂网络环境下的信息保密具有重要意义。

Complex network environments, such as multi-party communication environment and side-channel information leakage environment, pose new and higher challenges to the security of encryption schemes. Therefore, new tools must be found to re-design public key encryption schemes under new security models. Lossy trapdoor function is a new powerful cryptographic primitive proposed in recent years. It is an important tool to meet these challenges. We will study the constructions and applications of lossy trapdoor functions and their variants, including the following aspects: (1) new constructing ideas of lossy trapdoor functions, both based on general assumptions and concrete assumptions; (2) the application of lossy trapdoor functions in constructing high secure encryption schemes. We will study how to use lossy trapdoor function and related tools to construct more efficient high secure encryption schemes or schemes under stronger security model, such as chosen ciphertext secure encryption, selective opening secure encryption and leakage-resilient encryption schemes; (3) the variants of lossy trapdoor functions and more applications. Design lossy trapdoor functions with different properties based on the requirements in practical usage, such as lossy trapdoor functions with the chameleon property, anonymity, non-malleability and updatability, as well as ID-based lossy trapdoor function. This research will solve many important problems in the construction and application of the lossy trapdoor function, and is of great significance to information security in complex network environment.