动态存取控制新方案及其在特殊情况中的应用

在用户层次结构的动态存取控制问题上，本文提出了一种安全有效的方案。这一方隶是基于离散对数及多项式内插的方式，解决了指定的低层用户在高层用户缺席的情况下如何暂时代替高层用户执行部分权力的问题，以及在高层用户回来的情况下如何安全地收回权限的问题。

A New Dynamic Access Control Scheme and Its Applications in Exceptions

In the problem of dynamic access control, we present a secure and efficient scheme, which is based on discrete logarithms and polynomial interpolation. In our scheme, when a user at a higher level is absent, a certain user at a lower level can replace him and take the part of his privilege, and when the user at a higher level comes back, he can call back his privilege.