Topic

Implementing Cross Domain Solutions

Applicable to

Secret, Top Secret

History

Priority

must

Mar 2022

CDSs are implemented between SECRET or TOP SECRET networks and any other networks belonging to different security domains.

Miscellaneous changes were made to rationale and recommendations throughout the publication to clarify content without changing intent. This included a review from the Guidelines for System Hardening chapter through to the Guidelines for Data Transfers chapter.

Dec 2021

When connecting a SECRET or TOP SECRET network to any other network from a different security domain, a CDS is implemented.

Miscellaneous changes were made to rationale and security controls throughout the publication. This included:

• A review from the Using the Information Security Manual chapter through to the Guidelines for Media chapter.

• Security controls suitable for all audiences have been identified with the ‘All’ applicability marking while additional security controls suitable for just government audiences have been identified with the O, P, S and TS applicability markings.

• Security controls suitable for specific classifications have been amended to include their classification(s) in the wording of the security controls to reduce the reliance on applicability markings to confer suitability.

• Tables in security controls have been converted into prose to allow for inclusion in the SSP annex template and the XML list of security controls.

• The use of ‘official’ and ‘highly classified’ terminology has been replaced with specific classifications to remove ambiguity.

• Security controls relating to high assurance ICT equipment have had their applicability narrowed to ‘S, TS’ reflecting that they are intended for the protection of SECRET and TOP SECRET systems and data.

2015

Agencies connecting a TOP SECRET, SECRET or CONFIDENTIAL network to any other networkfrom a different security domain must implement a CDS.

2010

Agencies connecting a TOP SECRET, SECRET/HIGHLY PROTECTED or CONFIDENTIAL network toany other network from a different security domain must implement a cross domain solution.