近來Li等學者提出代理簽章的一般化簽署法，然而Li等學者提出方法具有一個共 同的安全弱點。在Li等學者方法中，攻擊者事先攔截某一代理群為其所代理的原 始簽章群所產生的代理簽章，攻擊者便可以偽造出相同於攔截訊息的代理簽章， 讓偽造的代理簽章看起來像是該代理群為攻擊者所簽署的代理簽章。 Recently, Li et al. proposed their generalization of proxy signature schemes. However, all of Li et al.'s schemes have a common security weakness. In Li et al.'s schemes, an adversary first intercepts a valid proxy signature generated by a proxy group on behalf of the proxy group G/sub p/. From the intercepted proxy signature, the adversary can forge illegal proxy signatures being like generated by the proxy group on behalf of an adversary.
Relation:
2003年全國計算機會議論文集 (Ⅲ)：二十一世紀資訊時代的挑戰=Proceedings of 2003 National Computer Symposium (Ⅲ)，頁1321-1324
