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Linked Data Access Goes Mobile: Context Aware Authorization for Graph Stores

  1. 1. LDOW2012   Lyon,  16  April   Linked Data Access 
 Goes Mobile" Context-Aware Authorization for Graph Stores! SELECT … ! WHERE {…}! Luca  Costabello,  Serena  Villata     Nicolas  Delaforge,  Fabien  Gandon  
  2. 2. Key Features" Background! WAC, [Abel et al, ISWC2007], [Finin et al.,SACMAT2008],[Flouris et al., FIS2010], [Sacco and Passant, LDOW2011], [Toninelli et al, ISWC2006]! Semantic Web Pluggable to languages only" any RDF store! > No new Policy languages! > SPARQL 1.1! Granularity from Mobile context in triples to whole graphs! the loop! > Named Graphs! > Context Awareness! [Carroll  et  al,  WWW2005]   [Schilit  and  Theimer,  94]     RDF  1.1   [Dey,  01]   2  
  3. 3. How it Works – Initial Setup" ●  Named Graph Partitioning! ! ●  Access Policy Definition! !S4AC & PRISSMA Vocabularies! 3  
  4. 4. Sample Access Policy" Protected resource Conditions to verify 4  
  5. 5. How it Works" 1.  Query Contextualization ! !! INSERT DATA { ! SELECT … ! U +   GRAPH :ctx1{! WHERE {…}! P [! ! ! U P ,! ]! ,! , …! :ctx1! }}! 5  
  6. 6. How it Works" 2.  Access Policy Evaluation! ASK {?context ! a prissma:Context; ! prissma:environment ?env.! ?env prissma:currentPOI ?poi. ! ?poi prissma:radius "500";! foaf:based_near ?p. ! =   "false"   ?p geo:lat "43.615811";! geo:long "7.068532".} ! BINDINGS ?context {(:ctx1)}! U P 6  
  7. 7. How it Works" 3.  Query Execution on Accessible Named Graphs! :ng1 ! :ng2 ! SELECT … ! :ng3 ! WHERE {…}! SELECT …! FROM :ng2,:ng3! FROM NAMED :ng2,:ng3! WHERE {…}! 7  
  8. 8. Response Time Evaluation" RDF  store  and  SPARQL  1.1.  engine:  Corese-­‐KGRAM  with  Berlin  SPARQL  Benchmark  Dataset  3.1   • Dataset size still predominant! • More context updates, ! more consumers" à Slower! • Small fraction granted" à Faster!
  9. 9. Future Work" Privacy"                         Context data User-centered trustworthiness" evaluation" Luca  Costabello  |  Serena  Villata    |  Nicolas  Delaforge  |  Fabien  Gandon   @lukostaz " " @serena_villata @ndelaforge" " @fabien_gandon" tinyurl.com/shi3ld

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