Example of security label dominance

The following example illustrates dominance of security labels when the subject is not allowed to write down:

Assume your system includes the following three security labels:
  • SECLABEL = PURPLE
    • SECLEVEL = SECRET
    • CATEGORY = PROJECTA, PROJECTB, PROJECTC
  • SECLABEL = COLUMBIA
    • SECLEVEL = SENSITIVE
    • CATEGORY = PROJECTA, PROJECTB
  • SECLABEL = UNION
    • SECLEVEL = UNCLASSIFIED
    • CATEGORY = PROJECTC
SECLABEL SECLEVEL CATEGORY
PURPLE SECRET PROJECTA, PROJECTB, PROJECTC
COLUMBIA SENSITIVE PROJECTA, PROJECTB
UNION UNCLASSIFIED PROJECTC
In this example:
  • PURPLE dominates COLUMBIA because the hierarchical security level SECRET is greater than the security level SENSITIVE and PURPLE's non-hierarchical categories include all of COLUMBIA's categories.
    Security level Project A Project B Project C
    Secret SECLABEL= PURPLE
    Sensitive SECLABEL= COLUMBIA no label defined
  • PURPLE also dominates UNION because the hierarchical security level SECRET is greater than the security level UNCLASSIFIED and PURPLE's non-hierarchical categories include all of UNION's categories.
    Security level Project A Project B Project C
    Secret SECLABEL= PURPLE
    Unclassified no label defined no label defined SECLABEL=UNION
  • COLUMBIA does not dominate UNION. It is true that COLUMBIA's hierarchical security level is greater than the security level of UNION. However, COLUMBIA's non-hierarchical categories (Project A, Project B) do not include all categories for UNION (Project C).
    Security level Project A Project B Project C
    Sensitive SECLABEL= COLUMBIA no label defined
    Unclassified no label defined no label defined SECLABEL = UNION
Parent topic: The subject is not allowed to write down