Subject, object, operation and permission

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We use the terms '''subject''', '''object''', '''operation''' and '''permission''' consistently with a standard access control literature.
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== Definition ==
== Definition ==
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In general, the set of existing objects and subjects changes over time.
In general, the set of existing objects and subjects changes over time.
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'''Permissions''' is a relation that defines which operations on what objects are permitted for particular subjects.
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'''Permissions''' is a relation that defines which operations on what objects are permitted for particular subjects. One way how to capture permissions is the [[protection matrix]].
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== Notes ==
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People (outside capability community) often confuse the following two terms:
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* '''permissions''' (defined in this article)
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* and [[authority]].
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Real security audit cannot be performed without determining the [[authority]] of particular '''subjects'''.
== See also ==
== See also ==
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Description of similar notions can be found in Section 5.5 (Protection Mechanisms) in [http://www.amazon.com/Operating-Systems-Implementation-Prentice-Software/dp/0131429388/ref=sr_1_14?ie=UTF8&s=books&qid=1245137182&sr=8-14 The MINIX Book].
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These are standard notions and they are defined in various other places:
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* in the [http://www.amazon.com/Operating-Systems-Implementation-Prentice-Software/dp/0131429388/ref=sr_1_14?ie=UTF8&s=books&qid=1245137182&sr=8-14 MINIX Book] (Section 5.5)
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* [http://en.wikipedia.org/wiki/Subject_(access_control)#Computer_security in Wikipedia].
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Latest revision as of 15:02, 14 March 2010

We use the terms subject, object, operation and permission consistently with a standard access control literature.

Definition

From a security point of view, we recognize subjects and objects

Subjects are active entities (e.g. UNIX processes) with some behavior. Subjects can designate objects and try to perform some supported operations with them.

What kind of operations can be performed with an object depends on its type.

In general, the set of existing objects and subjects changes over time.

Permissions is a relation that defines which operations on what objects are permitted for particular subjects. One way how to capture permissions is the protection matrix.

Notes

People (outside capability community) often confuse the following two terms:

  • permissions (defined in this article)
  • and authority.

Real security audit cannot be performed without determining the authority of particular subjects.

See also

These are standard notions and they are defined in various other places:

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