Controlling access in large partially ordered hierarchies using cryptographic keys

Abstract

The problem of access control in a hierarchy is present in many application areas. Since computing resources have grown tremendously, access control is more frequently required in areas such as computer networks, database management systems, and operating systems. Many schemes based on cryptography have been proposed to solve this problem. However, previous schemes need large values associated with each security class. In this paper, we propose a new scheme to solve this problem achieving the following two goals. One is that the number of keys is reduced without affecting the security of the system. The other goal is that when a security class is added to the system, we need only update a few keys of the related security classes with simple operations. (C) 2002 Elsevier Inc. All rights reserved.