基于证书加密方案通常将消息空间限制于某个特殊的群并且不适合大块消息加密.为了解决这一问题,将带标签的密钥封装机制引入到基于证书系统中,提出了带标签的基于证书密钥封装机制的形式化定义及安全模型.在此基础上构造了一个带标签的基于证书密钥封装方案,并证明了该方案在随机预言模型下是自适应选择密文不可区分的.
The certificate-based encryption schemes often limit the message space to a particular group and are not adaptive to encrypt large messages. In order to solve this problem, the study extends the concept of key encapsulation mechanism with tags to the certificate-based encryption, and then proposes the notion and security model of the certificate-based key encapsulation mechanism with tags (CB-TKEM). In addition, the paper presents a construction of CB-TKEM that is provably secure against IND-CCA2 in the random oracle model.