一個具有一般性存取結構的私密分享方法

Abstract

隨著電腦技術及網際網路應用的普及化，私密分享方法越來越重要。然而，一個複雜的私密分享方案通常意謂著1) 次密鑰大小不同，或2)主密鑰重建的步驟與存取結構有關。在這篇論文裡頭，我們提出了一個私密分享演算法，其可以建立具有以下特質的私密分享方案1)這些私密分享方案實現了一個類別的存取結構，2)每個次密鑰大小相同，3)次密鑰持有者不需要知道存取結構的任何資訊，且4)主密鑰重建的步驟不須考慮到存取結構。更進一步地，這個演算法還可以建立可更新的私密分享方案，意謂著更多的安全。

Secret sharing schemes are more and more important due to widespread computer technology and Internet application. However, a complex threshold scheme always means 1) share sizes are variant, or 2) the order of secret reconstruction operations is related to the access structure. In this thesis, we propose a secret sharing algorithm that can build a class of threshold schemes with some nice properties: 1) these threshold schemes realize a common class of access structures, 2) every share is of the same size, 3) share holders need not to know any information about the access structure, and 4) the order of secret reconstruction operations is not related to the access structure. Moreover, the proposed algorithm can be modified and then it can build updateable threshold schemes, which means more security.