对一种身份型广播加密方案的分析和改进

摘要

Identity-based broadcast encryption scheme using new techniques for dual system encryption,claimed the scheme could achieve full security and constant-size key and ciphertext in the standard model without tags.However,this paper showed that the proposal was not secure.Furthermore,this paper improved the scheme to be a secure one and proved its security in the standard model by using dual system encryption.%双系统密码技术下的身份型广播加密方案具有在标准模型下,尺寸固定的短密文和密钥,无须随机标签和全安全等特点.研究发现该方案是不安全的,进而提出了一种改进方案,并在标准模型下运用双系统密码技术给出了改进方案的安全性证明.