摘要： 介绍了多方访问结构的概念，在访问结构中，参与者集合被分为w个子集，同一子集中的参与者在系统中起到相同的作用。(t, n)-门限方案是在n个参与者当中共享原始秘密k的机制，使得至少要t个参与者才可以重构k。该文通过使用若干次门限方案构造出了可以实现所有多方访问结构的理想的秘密共享方案，并据此证明了多方访问结构是理想的访问结构。

关键词: 理想的秘密共享方案, 多方访问结构, 门限方案

Abstract: This paper introduces the concept of multipartite access structure. In this structure, the set of participants is partitioned into w subsets and all participants in the same subset play an equivalent role. The (t, n)-threshold scheme is a mechanism that allows a set of n participants to share a secret such that only subsets of t or more participants can recover it. This paper presents ideal secret sharing schemes that can realize multipartite access structures by using threshold scheme repeatedly and proves that multipartite access structures are ideal access structures.

Key words: Ideal secret sharing scheme, Multipartite access structure, Threshold scheme