Integration of authorization for grid

Today there are numerous authorization systems both for protecting and managing individual and distributed computer systems. Systems for authentication and authorization for distributed systems work only on software they were developed for. A complete system of authentication and authorization that works with different grid middleware is not yet developed. What can be done is to either implement a solution which is most adequate for a given distributed system and its purposes or try to make an adequate solution by combining multiple systems. In this paper we present problems and challenges when integrating authorization solutions of different grid systems. We present our experiences in enabling different systems to work together and describe extensions which we made in order to enable multiple authorization systems to work together