ISO/IEC 15408 is meant to be used as the basis for evaluation of security properties of IT products and systems. By establishing such a common criteria base, the results of an IT security evaluation will be meaningful to a wider audience.
Certain topics, because they involve specialized techniques or because they are somewhat peripheral to IT security, are considered to be outside the scope of ISO/IEC 15408. Some of these are identified below:
a) ISO/IEC 15408 does not contain security evaluation criteria pertaining to administrative security measures not related directly to the IT security measures. However, it is recognised that a significant part of the security of a TOE can often be achieved through administrative measures such as organisational, personnel, physical, and procedural controls. Administrative security measures in the operating environment of the TOE are treated as secure usage assumptions where these have an impact on the ability of the IT security measures to counter the identified threats.
b) The evaluation of technical physical aspects of IT security such as electromagnetic emanation control is not specifically covered, although many of the concepts addressed will be applicable to that area. In particular, ISO/IEC 15408 addresses some aspects of physical protection of the TOE.
c) ISO/IEC 15408 addresses neither the evaluation methodology nor the administrative and legal framework under which the criteria may be applied by evaluation authorities. However, it is expected that ISO/IEC 15408 will be used for evaluation purposes in the context of such a framework and such a methodology.
d) The procedures for use of evaluation results in product or system accreditation are outside the scope of ISO/IEC 15408. Product or system accreditation is the administrative process whereby authority is granted for the operation of an IT product or system in its full operational environment. Evaluation focuses on the IT security parts of the product or system and those parts of the operational environment that may directly affect the secure use of IT elements. The results of the evaluation process are consequently a valuable input to the accreditation process. However, as other techniques are more appropriate for the assessments of non-IT related product or system security properties and their relationship to the IT security parts, accreditors should make separate provision for those aspects.
e) The subject of criteria for the assessment of the inherent qualities of cryptographic algorithms is not covered in ISO/IEC 15408. Should independent assessment of mathematical properties of cryptography embedded in a TOE be required, the evaluation scheme under which ISO/IEC 15408 is applied must make provision for such assessments.
This part of ISO/IEC 15408 defines two forms for expressing IT security functional and assurance requirements. The protection profile (PP) construct allows creation of generalized reusable sets of these security requirements. The PP can be used by prospective consumers for specification and identification of products with IT security features which will meet their needs. The security target (ST) expresses the security requirements and specifies the security functions for a particular product or system to be evaluated, called the target of evaluation (TOE). The ST is used by evaluators as the basis for evaluations conducted in accordance with ISO/IEC 15408.