Malik Muhamamd Junaid Maximilian Berger Thomas Fahringer Distributed and parallel Systems Group University of Innsbruck Austria Oct, 13, Krakow, PL.

Outline Motivation Workflow Hosting Environment Secure Workflow Repository (SWFR) Architecture Components Security and Reliability Advancement Conclusion

Introduction Workflows are vital to Grid based applications. Increasing complexity of these applications is making the workflow design difficult, Leading to a need for: Workflow Sharing and Reuse Workflow security Workflow Version Management Workflow Modification History

ASKALON Workflow Storage Workflow Represented using AGWL based on XML Workflow storage is based on Filesystem Open access to all users Manual version history No Workflow Modification History No ownership record for workflows

Secure Workflow Repository(SWFR) SWFR is designed and implemented to address these issues: Features: Decentralized Service oriented implementation Secure Client Service communication for workflow transactions Extended Role Based Access Control Automated Version Control Comprehensive wokflow update history Complete Ownership information

Workflow Design Tool (client) Workflow Repository (Service) Architecture of the SWFR Event Handler Design Tool Repository Requests (Events) Repository Requests (Events) Authentication & Authorization Module Version Management Module Version Management Module Storage, Retrieval & Session Management Storage, Retrieval & Session Management Workflow Repository Session Manager

Permissions Security using Extended-RBAC Role based Access Control (RBAC) Opera tions objects Roles Users Role Hierarchy Permission Assignment Permission Assignment User Assignment Rights Delegation Extended Role based Access Control (E-RBAC) for Grid Workflows

Security using Extended-RBAC Request Handler Repository Access Authorization (E-RBAC) Authentication (RBAC) Session Authentication Decryption Layered Security Architecture: Request Handle performs Decryption of the incoming request based on the session information User Authentication based on Session and credential information Authorization check based on Roles and Exceptional rights Information Retrieval from the Repository Encryption using session information

Schema Diagram for the SWFR has change chg_type chg_id 1* has revision rev_nr time_st rev_Id * owner workflow name xmlid state 1 * has Wf_info Time_st count full_rev wf_inf_id has 1 * 1 * User u_id u_name name cred 1* u_perm rights * is_in ** Group gid Gp_name gp_perm rights * *

Automatic Version Management Version Management Module: Keeps track of the Existing Workflows in the Repository Applies Version Increment to the Updated workflows Automatic Minor updates for the workflow modifications User directed explicit major version updates

Conclusion SWFR Provides a better solution for workflow management It can be easily integrated into larger systems. Secure communication makes it safe for SOA Decentralized database makes it fast and efficient Layered Extended Role based access provides multi level of security. Fine grained access control is possible because of exceptional rights delegation Automatic version management helps in tracking changes and finding updated version easily.