XML Access Control for Semantically Related XML Documents

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____________________________

• XML Access Control for Semantically Related XML
  Documents
• A Role-Based Approach to Access Control For XML
  Databases
• BY
• Asheesh Kumar
• AXK0656
• April 27, 2006

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XML Access Control for Semantically Related XML
Documents________________________________________
_____

• Vijay Parmar and Hongchi Shi
• Department of Computer Science Computer
  Engineering
• University of Missouri- Columbia, USA
• Su-Shing Chen
• Dept of computer Information Science
  Engineering
• University of Florida, USA

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A Role-Based Approach to Access Control for XML
Databases________________________________________
_____

• Zingzhu Wang
• Department of Computer Science
• University of Western Ontario, Canada
• Su-Shing Chen
• Department of Computer Science
• University of Western Ontario, Canada

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XML Access Control for Semantically Related XML
Documents ________________________________________
_____

• XML most preferred way to store exchange
  information
• Need to provide controlled access to such
  information is imminent
• Authors propose an access control policy
  mechanism for a collection of semantically
  related XML documents

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XML Access Control for Semantically Related XML
Documents _______________________________________
______

• Features of proposed access control mechanism
• It is developed for XML documents- semantically
  related
• Access control conditions can be specified based
  on contents of the document
• Access control is role based

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XML Access Control for Semantically Related XML
Documents _______________________________________
______

• Assume that each XML document resembles an entity
  playing a certain role
• Each entity has certain relationships with other
  entities (XML document)
• An access request may result in data coming from
  more than one document in the collection
• Semantic relationships, so document playing a
  certain role can have access to other entities
  playing a different role

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Sample relationships of entities playing
  particular role

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Relationship between entities (XML documents)

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Observations for Access Control Policy
• XML documents are not accessed by the document
  names..
• Entity playing a role may requests data from
  collection of XML documents by giving a general
  request over the whole collection
• Now, requesting entities identification role
  would cause access control mechanism to restrict
  its access according to access control policy
• All documents in collection must comply with same
  DTD, so all entities playing a similar role have
  same structure but different content

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Overview of Access Control Policy Specification

The Access Control Policy DTD
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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Operation types and execution
• Read
• Write
• Create
• Delete
• Operations are performed by first querying
  the XML document collection with the XPATH query
  expression provided in the access request

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Steps involved in Read Operation
• XPath query is processed on collection of XML
  documents
• Results checked for list of allowed elements for
  read operation under the appropriate role
• Result of above step leaves a set of document
  fragment that is further checked for access
  control condition
• Condition for each allowed element and sub
  element is checked
• If conditions are satisfied, the content of
  allowed element are not deleted

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• A sample Read operation

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XML Access Control for Semantically Related XML
Documents ________________________________________
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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Condition Specification
• Conditions indicate constraint for the access to
  the particular allowed element for a specific
  operation
• Presence of name of an element in the allowed
  element list indicates that it is allowed for
  access for a particular role only if the
  conditions are satisfied
• Conditions can be specified in the access control
  policy document with the condition element
• AND OR conditions ..

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XML Access Control for Semantically Related XML
Documents _______________________________________
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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Condition types
• Prohibit
• Equals
• Exists
• NotExists

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• A sample Condition Specification

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• A student is not allowed to update his grades but
  allowed to view them

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XML Access Control for Semantically Related XML
Documents _______________________________________
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• Overall Access control model

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A Role-Based Approach to Access Control for XML
Databases _______________________________________
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• Propose to combine Role Graph Model,
  Authorization Type Graph and Authorization Object
  Schema, Authorization Object Graph
• Group of permission -gt Role -gt assigned to users
• Permissions are privileges
• Privileges are made up of object and access mode
  ( read/ write etc)
• Object part of an XML database is any part of XML

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A Role-Based Approach to Access Control for XML
Databases _______________________________________
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• Example Role Graph

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A Role-Based Approach to Access Control for XML
Databases _______________________________________
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• Authorization Object Schema for example

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A Role-Based Approach to Access Control for XML
Databases _______________________________________
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• Authorization Object Graph for example

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A Role-Based Approach to Access Control for XML
Databases _______________________________________
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• Authorization Type Graph

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A Role-Based Approach to Access Control for XML
Databases _______________________________________
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• Authorization Association Matrix

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• Thank You
• Asheesh Kumar
• AXK0656