在2018年，Shi等人表明，Kaushik等人的量子簽章方案存在缺陷。它遭受了偽造攻擊。他們進一步提出了改進措施，試圖避免這種攻擊。但是，經過檢驗，我們發現他們改進的量子簽章法是可以被否認的，因為驗證者可以冒充簽章者簽署一條訊息。此後，當發生爭議時，他可以辯稱簽章是來自簽章者，而不是他所簽的。為了克服這種缺點，在本文中，我們提出了更進一步的改進，使其成為一個真實可用的量子簽章，可以被公開的非特定驗證者所驗證，因此可以更實際應用於現實生活中。在密碼分析之後，我們確認我們改進的簽章法不僅可以抵禦偽造攻擊，而且是不可否認的。 In 2018, Shi et al showed that Kaushik et al's quantum signature scheme is defective. It suffers from the forgery attack. They further proposed an improvement, trying to avoid the attack. However, after examining we found their improved quantum signatureis deniable, because the verifier can impersonate the signer to sign a message. After that, when a dispute occurs, he can argue that the signature was not signed by him. It was from the signer. To overcome the drawback, in this paper, we proposed an improvement to make it a practical signature to be publicly verified and can be applied in real life. After cryptanalysis, we confirm that our improvement not only can resist the forgery attack but also is undeniable.
