PD-0055: Effect of Addition of Environmental Assumptions on PP Compliance

This decision represents a long-term technical decision based on an OD, and may not be the same as the final results of the source OD. With respect to published criteria documentation and scheme documents, it provides suggested guidance on evaluation direction, but is not authoritative. Authoritative decisions are provided through the published criteria documents and published scheme and international interpretations thereof. With respect to published PPs, PDs are authoritative corrections to the PP, based on input from the PP author (if available), that are in force until the publication of the next revision of that PP.

Issue

Does the addition of assumptions on the environment violate PP compliance?

Resolution

The CC/CEM does not directly address whether additional assumptions (above and beyond those found in the PP) in an ST disallows PP compliance. However, it is reasonable to allow additional assumptions in the ST if the original intent of the PP assumptions has not been violated: the additional assumptions must not change the environment in such a way that affects the TOE's meeting of its stated objectives, nor can the new assumptions change an objective from a TOE objective to an environmental objective. In cases where additional assumptions merely add implementation detail that limits the acceptable implementations (and, hence, could be viewed as "refinements" to the environmental assumption statements), the evaluator analysis must show that the additional TOE environmental assumptions do not strengthen the TOE environment in such a manner that weakens the TOE by relegating required TOE functionality (by the PP) to the TOE Environment.

When new assumptions are identified, the evaluation team must document the analysis of the additional assumptions in the ETR, offering rationale that the original intent of the PP assumptions remains in tact.

Modification History:

2004-08-12

Updated effective date to reflect the date the PD was issued. (August 2004 NIB 6.c.xiv)

References:

• CEM v1.0 Part 2 Clause 4.4.5 ASE_PPC

Related NIs:

• I-0378: Meaning Of Compliance Claims

Related CCIMB-INTERPs:

• None

Source OD: 0198