A method relates to access control of shared resources on computer systems that have diverse system policies for access rights to resources. The method includes, on a source computer system with which a target computer system shares a resource, preparing user-authorization data for the shared resource in a flat file format as data tuples, line records or tables. This format makes the user-authorization data usable in computer systems with diverse system policies for access rights to resources. The method further includes authorizing user access to the shared resource on the target computer system based on the user-authorization data prepared in flat file format by the source computer system.