Changes between Version 28 and Version 29 of TIEDABACDemo


Ignore:
Timestamp:
07/13/09 18:24:20 (10 years ago)
Author:
faber@isi.edu
Comment:

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  • TIEDABACDemo

    v28 v29  
    141141=== Negotiating Access ===
    142142
    143 While the global graph is somewhat daunting in its complexity, it is important to realize that any single access decision requires the construction of only one path from principal to attribute.  The two endpoints construct a graph together from their credentials, each of which represents an edge in the visualization above.  For example, the case where faber is authenticating to the slice requires proving that faber has the GENI.CTFadmin credential.  The slice has the following relevant credential:
     143While the global graph is somewhat daunting in its complexity, it is important to realize that any single access decision requires the construction of only one path from principal to attribute.  The two endpoints construct a graph together from their credentials, each of which represents an edge in the visualization above.  For example, the case where faber is seeking authorization to access the slice requires proving that faber has the '''GENI.CTFaccess''' credential.  The slice has the following relevant credentials:
    144144
    145145[[Image(example1.png)]]
     146
     147and
     148
     149[[Image(example4.png)]]
     150
     151and
     152
     153[[Image(example13.png)]]
    146154
    147155And faber holds:
     
    149157[[Image(example11.png)]]
    150158
    151 The simplest exchange is that faber requests access, the slice sends its relevant credential as a starting graph and faber responds with the completed graph:
     159The simplest exchange is that faber requests access, the slice builds a graph of all the credentials that might be part of a path from principal to credential, and sends them to faber.  That message contains credentials that represent this graph:
    152160
    153 [[Image(example12.png)]]
     161[[Image(example15.png)]]
    154162
    155163Each side can check all the credentials to make sure the reasoning is sound.  The credentials only fit together one way so they agree on the proof.  At that point the authorization is complete.