Analysis indicates that it is secure against the proxy signer's forgery attack, and even against the malice attack of the ally of the proxy signer and the PKG. 針對此方案的缺陷,提出了改進(jìn)措施,分析表明改進(jìn)后的方案是安全的,可抵抗代理人惡意的偽造攻擊,還可以抵抗代理人和私鑰產(chǎn)生中心聯(lián)合的惡意攻擊。