The purpose of these requirements is to:
- provide a common set of definitions and a consistent approach to categorising security risks and impacts across government
- help agencies to consistently assess business impacts across New Zealand government responsibilities
- provide a structured approach to determining the impacts of the loss or compromise of information, people and/or assets
- assist agencies to manage security risks by informing the identification of appropriate controls and providing assurance when information is shared between agencies.
The audience of these requirements is personnel within the New Zealand government responsible for defining the Business Impact Levels (BILs) relating to the security of government assets, including information and Information and Communications Technology (ICT) systems, including:
- New Zealand government security management staff
- contractors to the New Zealand government providing security advice and services
- any other body or person responsible for the security of New Zealand government people, information or assets.
The New Zealand government needs standardised and scalable security-focused BILs that can be associated with assets of different sensitivity and trust levels.
Common definitions will allow agencies to effectively share the implications of particular risks with their partners.
These requirements relate to protective security measures:
- within New Zealand government facilities
- within other facilities handling New Zealand government information and assets
- where New Zealand government personnel are located.
Where legislative requirements are higher than controls identified in these requirements the legislative controls take precedence and should be applied.
1.4 Compliance requirements
A control with a ‘must’ or ‘must not’ compliance requirement indicates that use of the control is mandatory. These are the baseline controls unless the control is demonstrably not relevant to the respective agency and can be clearly demonstrated to the agency head or accreditation authority.
A control with a ‘should’ or ‘should not’ requirement indicates that use of the control is considered good and recommended practice. Valid reasons for not implementing a control could exist, including:
- a control is not relevant because the risk does not exist
- or a process or control(s) of equal strength has been substituted.
Agencies must recognise that not using a control without due consideration may increase residual risk for the agency. This residual risk needs to be agreed and acknowledged by the agency head. In particular an agency should pose the following questions:
- Is the agency willing to accept additional risk?
- Have any implications for All of Government security been considered?
- If so, what is the justification?
A formal auditable record of this consideration and decision is required as part of the governance and assurance processes within an agency.
The PSR provides agencies with mandatory and best practice security measures.
The controls detailed above describe if and when agencies need to consider specific security measures to comply with the mandatory requirements.