Horst F. Wedde 

(Professor of Computer Science at the University of
Dortmund, Germany) 

Time : Tuesday, May 08 2:00-3:00 p.m.

Location: SB 111

Modular Authorization

Abstract

There are three major drawbacks of a centralized security administration in distributed systems: It creates a bottleneck for request handling, it tends to enforce homogeneous security structures in heterogeneous user groups and organizations, and it is a weak point in terms of security attacks, reliability, and fault tolerance. In this paper we introduce a distributed authorization concept which is based on a modular authorization language for supporting cooperating distributed authorization teams. These teams are partially ordered into a hierarchy in that they inherit authorization rules from higher order teams but still exercise their autonomy by (dynamically) setting local rules that serve the special local needs in distributed organizations. Conflicts between between rules inherited from different higher ranking sources, or violations of higher order rules through local rules would be detected, on the logical level or through request evaluation, as contradictions or contradicting results, respectively. Conflict resolution mechanisms are presented, and examples are discussed extensively.  

 

Short Bio of the Speaker

Horst F. Wedde is a full professor of Computer Science at the University of Dortmund, Germany, since 1994. Prior to this appointment he was on faculty at Wayne State University, Detroit (1984-1993), and serving as a senior staff researcher and project leader at the GMD (German National Research Institute for Computer Science) (1969-1983). He also held visiting positions at the Universities of Pisa, Turin, Naples (Italy), the Polish
and Russian Academy of Sciences, and elsewhere in Europe and Mexico. He has well over a hundred publications to his credit.

His major research interests are in distributed systems, operating systems, real-time/ safety-critical systems, distributed security, formal modeling and analyzing distributed systems.