Hierarchies arise in the context of access control whenever the user population can be
modeled as a set of partially ordered classes (represented as a directed graph). A user with …

The widespread adoption of XML holds out the promise that document structure can be
exploited to specify precise database queries. However, the user may have only a limited …

Many group communications require a security infrastructure that ensures multiple levels of
access privilege for group members. Access control in hierarchy is prevalent in multimedia …

A key assignment scheme is a cryptographic technique for implementing an information flow
policy, sometimes known as hierarchical access control. All the research to date on key …

A minimization problem is proposed to combine smoothing of locally computed motion data
(eg normal flow) with the detection of motion boundaries. The continuous formulation of the …

4,864,616 A 9, 1989 Pond et al. 4,879,747 A 11/1989 Leighton et al. 5,210,795 A 5/1993
Lipner et al. 5,721,781 A 2f1998 Deo et al. 5,754,675 A 5/1998 Valadier 5,832,091 A …

The erosion of trust put in traditional database servers and in Database Service Providers,
the growing interest for different forms of data dissemination and the concern for protecting …

Foreword by Pierangela Samarati Privacy requirements have an increasing impact on the
realization of modern applications. Commercial and legal regulations demand that privacy …

Access control to confidential information in pervasive computing environments is
challenging for multiple reasons: First, a client requesting access might not know which …

The need for content access control in hierarchies (CACH) appears naturally in all contexts
where a set of users have different access rights to a set of resources. The hierarchy is …