Information Technology Reference
In-Depth Information
RepositoryObject
Role
Guideline
Objective
Rule
Activity
Object
Subject
Agent
SecurityPolicy
Domain
has
Metapolicy
isA
Fig. 2.
Basic conceptual model of the SPR
5.1
Step I: Resolution of Conflicting Objectives
The detection and resolution of conflicting security objectives is a prerequisite for
addressing more specific conflicts. Although this process cannot be performed auto-
matically, the SPR facilitates the process through the structured representation of
security objectives.
5.2
Step II: Semantic Heterogeneity Resolution
It is normal for policies that have been conceived and formulated by different authors
to use concepts and terms differently. Due to this fact many conceptual discrepancies
may arise. Examples of conceptual discrepancies include the homonyms problem,
where two diverse entities are referred with the same term, and the synonyms prob-
lem, where different terms refer to the same entity. The detection of discrepancies can
be considered as an instance of the semantic heterogeneity problem.
That is how to decide whether given incomplete and heterogeneous sets of repre-
sentation symbols refer to the same underlying reality [8]. Various techniques have
been proposed for detecting and resolving semantic conflicts in areas such as multiple
requirement specifications [9] and multiple database systems, e.g. federated databases
[10].
5.3
Step III: Resolution of Domain Overlapping
Domains consist of activities performed by agents that use resources (i.e. objects).
Domain overlapping is a common cause of conflict occurring when two or more poli-
cies apply to the same domain elements. The problem arises when agents performing
an activity have to obey conflicting rules posed by different policies. These conflicts
can be resolved by adopting one of the following methods:
−
Policy modification
. One of the policies is either modified or cancelled. This pro-
cedure involves negotiations that may lead to mutual agreements on the needed
modifications.
