25 inference channel informabon transfer path by which

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Unformatted text preview: nsert),grant Alice X (read,update),grant Bob {X:R,U,I},grant t3 Carol X (read,update),grant Bob Carol Bob {X:R,U,I},grant {X:R,U},grant t4 Alice Revoke X (read,update,insert) Bob •  What privileges do Bob and Carol have now? 21 {X:R,U,I},grant RevocaBon Rules •  Not standard •  Many implementaBons follow convenBon: “When User A revokes an access right, any cascaded access right is also revoked, unless that access right would exist even if the original grant from A had never occurred.” ApplicaBon to our examples? Disadvantages to SQL Model •  Too many views to create –  Tedious for many users, each with their own view –  View redefiniBons that change the view schema require dropping the view, redefining, then reissuing privileges –  Fine- grained policies each require their own view— and no obvious way to see that the views come from the same table •  ApplicaBons oXen use one user and implement own access control •  Other techniques being developed but not yet widely deployed 23 Types of InformaBon Disclosure •  Exact data –  Show the student's GPA aMribute •  NegaBve result –  See aggregate cou...
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This note was uploaded on 02/03/2014 for the course ECE 422 taught by Professor Nicol during the Fall '08 term at University of Illinois, Urbana Champaign.

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