两种无证书签密方案的密码分析和改进  

CRYPTANALYSIS AND IMPROVEMENT OF TWO CERTIFICATELESS SIGNCRYPTION SCHEMES

作　　者：樊爱宛[1] 潘中强[2] 赵伟艇[1] 

机构地区：[1]平顶山学院软件学院,河南平顶山467002 [2]平顶山学院网络计算中心,河南平顶山467002

出　　处：《计算机应用与软件》2016年第7期313-317,333,共6页Computer Applications and Software

基　　金：河南省高校青年骨干教师资助计划项目;河南省科技攻关计划基金项目(152102210193);河南省高等学校重点科研项目(15A520091)

摘　　要：对两种新提出的无证书安全签密方案进行密码学分析,证明这两种方案都是不安全的。对于第一种方案,不仅使主密钥泄露,而且在类型Ⅰ和类型Ⅱ敌手攻击下是无法保证机密性和抗伪造性。对于第二种方案,在类型Ⅰ敌手攻击下,不仅可以利用公钥替换伪造任何用户对任意消息的签密,而且可以冒充合法接受者解签密消息。利用公钥与哈希函数绑定、增加随机数和公钥配对参与运算的方法,分别对它们进行改进。在随机预言机模型中,对改进方案进行安全性证明,表明改进方案是安全的。Applying the cryptanalysis to two newly presented certificateless secure signcryption schemes,it is proved that both of them are insecure. For the first one,not only the master key can be disclosed,it cannot ensure the confidentiality and anti-forgery capability under the attacks made by type I and type II adversaries as well. For the second scheme,under the attack launched by Type I adversary,not just the public key can be used to replace and forge the signcryption by any user on arbitrary message,but the legitimate recipient can also be feigned to calculate the signcryption. We improved these two schemes separately by means of binding the public key and hash function,increasing the random numbers and participating in operation with public key pair. In random oracle model we proved the security of the improved schemes,they were demonstrated secure.

关 键 词：无证书签密 机密性攻击 伪造性攻击 公钥替换 随机预言机模型 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]