一个基于分级身份的密码系统

A Hierarchical Identity-Based Cryptosystem

提出一个基于分级身份的密码系统:包括分级的基于身份的加密和签名方案。在随机预言模型下,新的基于分级身份的加密和签名方案都是可证明安全的,同时在标准模型下,基于分级身份的加密方案是在给定身份攻击下可证明安全的。基于给出的基于分级身份的加密方案,首次提出了分级代理解密的概念,并且给出了安全模型和构造方法。

A new hierarchical identity based （ID-based） cryptosystem is proposed, including hierarchical ID- based encryption and signature. In random oracle model, both hierarchical ID-based encryption and signature schemes are provably secure. Furthermore, the new hierarchical ID-based encryption scheme is secure under selective-ID attack in standard model. Furthermore, the notion of hierarchical proxy decryption is first proposed. Meanwhile, the security model and a generic construction method for proxy decryption are also presented.