Abstract: This paper analyzes the security of a certificateless signcryption scheme, which includes confidentiality and unforgeability. It is shown that the scheme is insecure. It can not resist the attack of the second type Ⅱand adversary A2, the attack process is gives in detail. Analysis result shows the scheme can not meet confidentiality, it can produce random forgery, and it is unsafe.

Key words: certificateless, signcryption, bilinear pairing, confidentiality, unforgeability

摘要： 分析一种可公开验证的无证书签密方案，从机密性和不可伪造性2个方面对无证书签密方案进行安全性分析，证明该方案不能抵抗类型Ⅱ和敌手A2的攻击，并给出具体的攻击过程。分析结果表明，该方案不满足机密性，还可以产生任意的伪造，是一种不安全的无证书签密方案。

关键词: 无证书, 签密, 双线性对, 机密性, 不可伪造性

CLC Number: 

• TP309