针对5个文献中所提出的标准模型下的签密方案进行了安全性分析.指出它们或者存在恶意但被动的KGC(Key generation center)攻击、或者存在内部攻击者的保密性攻击、或者存在内部攻击者的伪造性攻击、或者存在选择明文攻击.通过这些攻击,攻击者或者可以伪造一个签密文、或者可以破坏方案的保密性.最后表明要设计标准模型下安全的签密方案仍然是一个值得研究的问题. A security analysis of the signcryption scheme under the standard model proposed in the five documents was conducted, which indicated that they either had a malicious but passive Key Generation Center (KGC) attack, or had an internal attacker’s privacy attack or existed internal The attacker’s counterfeit attack, or the choice of plaintext attack, can be exploited by an attacker to forge a signed ciphertext, or to undermine the confidentiality of the scheme.Finally, it is shown that the security scheme to design a standard model remains the same Worth to study the problem.