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Access Control in Collaborative Systems. William Tolone , Gail- Joon Ahn , Tanusree Pai & Seng -Phil Hong. Outline. Collaborative Environments Access Control Requirements Access Control Models Assessment Conclusion. Collaborative Environments. Facebook Code Repositories Webcourses.
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Access Control in Collaborative Systems William Tolone, Gail-JoonAhn, TanusreePai & Seng-Phil Hong
Outline • Collaborative Environments • Access Control Requirements • Access Control Models • Assessment • Conclusion
Collaborative Environments • Facebook • Code Repositories • Webcourses
Access Control Requirements • Applied at a distributed level • Should be able to adapt • Scalability • Fine-grained control • Exclusion of unauthorized users • Easy specification of access rights • Ability to dynamically change access policies • Reasonable performance and resource cost
Outline • Collaborative Environments • Access Control Requirements • Access Control Models • Assessment • Conclusion
Access Matrix Model • Based on subjects and objects • Reference monitor for checking access rights
Access Matrix Model (cont.) • Implemented in Access Control Lists
Access Matrix Model (cont.) • Shortcomings • Not complex enough • No ability to dynamically change policy • Can’t address objects not owned by users
Roll-Based Access Control(RBAC) • Permissions assigned to roles rather than users • Users associated to roles • More scalable • Shortcomings • Roles are too static
Task-Based Access Control(TBAC) • Derivative of subject-object model • Contains information based on task • Access granted in steps related to the task • Active model • Shortcomings • Context only based on task progression • Management, delegation, revocation are not covered • Not very applicable outside enterprise • May use roles as an interface
Team-Based Access Control(TMAC) • Similar to RBAC • Covers case when different roles collaborate together • User context describes user’s role in team • Shortcomings • Hasn’t fully been developed
Spatial Access Control • Divides collaboration environment into regions • User credentials used to determine access • Shortcomings • Only navigational access requirements • Must divide application into regions
Context-Aware Access Control • Extension of RBAC • Environment roles defined at time of activation • Shortcomings • Hasn’t been fully developed/tested
Outline • Collaborative Environments • Access Control Requirements • Access Control Models • Assessment • Conclusion
Assessment • Criteria • Complexity • Transparency • Ease of use • Applicability • Collaboration Support • Policy Specification • Policy Enforcement • Fine Grained Control • Active/Passive • Contextual
Conclusion • Roles are well accepted • Importance of context • Active systems are preferable • Scalability required