两种基于身份的广播加密方案的安全性分析

摘要

The security of the two identity-based broadcast encryption schemes proposed by Sun Jin et al was analyzed and their security flaws were pointed out.In the broadcast encryption scheme,any user with the correct private key can act as PKG to produce private keys for other users.In the second scheme,the random number s should be revealed for decryption.Once s is published,however,any person can decrypt the ciphertexts.Therefore,the two broadcast encryption schemes are insecure.%针对孙瑾等提出的两种基于身份的广播加密方案进行了安全性分析,指出这两种方案存在安全缺陷.在第一种广播加密方案中,任何拥有合法私钥的用户都能冒充PKG给其他用户发布私钥.第二种广播加密方案的解密过程需要公开随机因子s,而s一旦公开,任何人都可以解密密文.因此,这两种广播加密方案都是不安全的.