AN AUTHORIZATION MODEL FOR A DISTRIBUTED HYPERTEXT SYSTEM

Digital libraries support quick and efficient access to a large number of information sources that are distributed but interlinked. As the a mount of information to be shared grows, the need to restrict access o nly to specific users or for specific usage will surely arise. The pro tection of information in digital libraries, however, is difficult bec ause of the peculiarity of the hypertext paradigm which is generally u sed to represent information in digital libraries, together with the f act that related data in a hypertext are often distributed at differen t sites. In this paper, we present an authorization model for distribu ted hypertext systems. Our model supports authorizations at different granularity levels, takes into consideration different types of data a nd the relationships among them, and allows administrative privileges to be delegated.