1. 1 Context-base Access Management in Ubiquitous Environment 윤혜진 2007-08-10

2. 2 Cotnents  Access Control Issues in Ubiquitous Environments  UbiCOSM Security Framework Security Model Access Control Middleware  Case Study: Mobile Office Application  Conclusions and Future Work

3. 3 introduction  Wireless network connectivity and portable devices anywhere and at anytime access from various access devices  Novel access control challenges: Paradigm shift from subject-centric to context-centric access control  Un-informative identity or not trustworthy  Traditional identity-based access control models are inadequate for Ubiquitous Environments  Static characterization of context

4. 4 UbiCOSM Security Framework UbiCOSM (Ubiquitous Context-based Security Middleware) Permissions are directly associated with contexts Context=grouping mechanism for applicable permissions Goal: Immediate Controlled visibility of accessible resources and of other mobile users locally executing

5. 5 UbiCOSM Context Model context Physical ContextLogical Context Resource Tourist Logical MonitoringSystem.GetVisitNumber.IsLess(N) ResourceManager.GetInfo(Spiderman Movie) Cinema Physical GeoCoordinate.IsEqual(Area.GetInfo)

6. 6 Metadata Profiles Access Control Policies System Control PoliciesSecurity Waves a ….. nearby cinemas Spiderman movie find vacant seats always anywhere within 3 km b UbiCOSM Security Model

7. 7 p1 see pos a b AdultP1<Simple(Adult,P1) Waiting Room P2 Cinema Hall P3 P4 Tourist Waiting Room Tourist Tour Guide Access Control Policy Specific context conditions specific permissions

8. 8 UbiCOSM architecture

9. 9 And(hasSeat(N), desireMovie(movieName) Simple(isNotFull) And(FarFromCinema, InQueue) And(friend, relative) p2 find_a_cinema pos p3 insert_an_opinion(myOpinion) pos p4 book_Ticket(N) neg p1 retrieve_opinion pos a b c d