有安全性往前遞移特性的代理簽章方法

Abstract

目前，電子交易日漸盛行；此外，任務的指派、機密文件的傳送…等也逐漸利用網際網路來完成，所以，在電腦世界裡，電子簽章的使用是不可或缺的。代理簽章的方法首先在1996提出，電子簽章的使用者可以用代理簽章的方法，來授權他的簽章能力給代理簽章者。而另一方面，私密金鑰被其他入侵者得到是電子簽章在安全上最大的威脅，這是因為若私密金鑰被被外人得知，利用此金鑰所簽的所有電子簽章都無法再信任，不管該簽章是否在金鑰洩密前就產生。在「安全性向前遞移的電子簽章」這篇論文中所提到的觀念 – “安全性向前遞移”是不錯的解決方法。因此，在本篇論文提出了一個新的代理簽章方法，並且利用這個代理簽章法再結合安全性向前遞移的觀念，創造出另一個更安全的代理簽章方法。

Nowadays, an electronic transaction is more and more popular. Besides, not only designing a job but also sending secret document is through the Internet. Thus, the digital signature scheme is indispensable to the electronic would. Proxy signature scheme was proposed in 1996, which makes original signers be able to delegate his digital signature signing capability to a proxy signer. On the other way, the greatest problem against the security of a digital signature scheme is exposure of the secret key, because we cannot trust all signatures singed by this key even the signature was signed before the key is compromised. Forward secure, which is proposed in ”A Forward-Secure Digital Signature Scheme”, is a better solution to reduce the damage. This paper proposes a new proxy signature scheme and then combines forward secure property to this proxy signature to make it more invulnerable.