Abel 2007 Medha Question 2
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- Question is for the Presentation: Abel2007enabling presented by Tim Lebo 25 sept 2008
- Question is asked by: Medha Atre
- The Question is: ONE: The given example is a very tiny one w.r.t original query and set of policies defined. Is there any estimate available about what is the number of typical policies on a decent size RDF triple store. TWO: How big a transformed query turns after applying all the policies (THREE:) and especially if multiple policies defined by multiple people get applied? The paper says that if deny policy is applicable then access triple is denied, but then this generic approach doesn't seem to embrace some user's preference to allow access to some information, unless a within policies is provided. E.g. Alice says allow access to (l3s:alice, foaf:phone, Z) and Harry says deny access to (X, foaf:phone, Z)?
Response: ONE: The 'tiny' example discussed in the paper kept small for pedagogical purposes. The paper does not suggest any statistics on the size of policies in use today. One reason for this is that policy-based RDF access control is not a standard practice. TWO: Your inquiry motivates a consideration for the number of /possible/ policies, which is an aspect that should be considered in future investigations. One caveat is that the number of policies is domain and application dependent. The size of a transformed query is a function of the query's path expressions and the policies' head (triple) and body (path expressions and boolean expressions). The function is enumerated in paper. THREE: Policy management is a well studied field and an overview is out of scope for this paper. The contribution of this paper is the use of a policy language to rewrite an incoming query to prevent unauthorized access. The paper refers to reference kaga2003policy for advanced algorithms to exploit priorities and default precedences among policies.warning.pngString representation ONE: The 'tiny' example discussed in the p […] es and default precedences among policies. is too long.
| Question asked | ONE: The given example is a very tiny one … ONE: The given example is a very tiny one w.r.t original query and set of policies defined. Is there any estimate available about what is the number of typical policies on a decent size RDF triple store. TWO: How big a transformed query turns after applying all the policies (THREE:) and especially if multiple policies defined by multiple people get applied? The paper says that if deny policy is applicable then access triple is denied, but then this generic approach doesn't seem to embrace some user's preference to allow access to some information, unless a within policies is provided. E.g. Alice says allow access to (l3s:alice, foaf:phone, Z) and Harry says deny access to (X, foaf:phone, Z)? ry says deny access to (X, foaf:phone, Z)? |
| Question asked by | Medha Atre + |
| Question for the Presentation | Abel2007enabling presented by Tim Lebo 25 sept 2008 + |
| Response | warning.pngString representation ONE: The 'tiny' example discussed in the p […] es and default precedences among policies. is too long. |
