Barker, KennethChu, Nelson Chung Ngok2013-01-312013-06-152013-01-312013Chu, N. C. (2013). Dynamic Role Lease Authorization Protocol for a Distributed Computing System (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25761http://hdl.handle.net/11023/539A distributed computing system, such as a Grid, could be a very dynamic environment and the user groups are most likely become highly diverse. A user group could be formed by the users of different networks, organizations, or administrative-domains with different hardware/software infrastructures and managerial policies. Handling requests from a wide range of users from different domains becomes a challenge when attempting to accommodate all the differences. Service providers find it impossible to track all users (the number of users could be potentially very large) in a Grid. Therefore, an access control mechanism that provides users appropriate access to the resources in a dynamic environment is required. Role Based Access Control (RBAC) models have been demonstrated to be an effective and efficient approach for an administrator to manage accesses in a computing system. Much has been done to adapt the RBAC concept to Grids and focus on the authorization and verification of the dynamic factors or contexts of a user, such as time, location, rank, etc. Some applications also allow administrators to change the policies during the authorization process, but they did not handle the authorization in real-time and on-demand manner in a Grid. It is a critical authorization requirement for a dynamic environment. Therefore, this problem motivated us to develop a new dynamic authorization protocol, Dynamic Role Lease Authorization (DRLA) that is suitable for a dynamic distributed computing environment.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Computer ScienceAuthorizationRBACLeaseGriddoctoral thesis10.11575/PRISM/25761