Optimistic anonymous participation in inter-organizational workflow instances

Electronic business applications are often structured by workflow declarations that span potentially numerous generic activities in different organizations. Such declarations are used to assign activities to specific entities, and to dynamically grant and revoke access to the resources according to the execution state of the workflow instance. If competing organizations cooperate in common workflow instances for achieving a joint purpose, they might want to let entities participate anonymously. Anonymous participation demands a restricted flow of identifying information, whereas state dependent access control requires the flow of specific control information. In this paper we introduce the 'Anonymous SDSD' approach (State-Dependent Security Decisions) balancing the conflicting requirements by combining techniques like onion routing, logging, bulletin boards, pseudonyms and proxies.