普适安全的基于身份的签名机制

摘要

Idea Functionality is the core and basic unit of Universally Composable (UC) security protocols. The first step of designing the protocols, within the Ucsecurity framework, is to extract an ideal functionality from the expected functionalities of the protocols. To appropriately define an ideal functionality we should not only protect the security of the definition, but also consider the realizability.This study investigates the security of identity-based signature (IBS) within the Ucframework,defines a realizable identity-based signature functionality F^, proves that UC-secure IBS is equivalent to conventionally-secure (EUF-CMIA -secure) IBS. As a result, we are able to make sure that the EUF-CMIA scheme can be a module in designing a complex protocol that satisfies the Ucrequirement.%理想功能是UC安全协议的基本单元和核心内容.在UC安全框架下协议设计的首要步骤就是要将协议所希望完成的功能抽象为一个“理想功能”,“理想功能”的合理定义不仅要从定义上保证安全,更重要的是要兼顾其可实现性.本文定义了基于身份的签名机制(IBS)在UC安全框架下对应的理想功能FIBS,证明了其可实现性以及UC安全的IBS与经典IBS安全定义EUF-CMIA安全之间的等价关系,保证了在构造复杂环境下UC安全协议的时候,EUFCMIA安全的IBS可以作为一个模块被安全调用.