ISM-0231

When using cryptographic equipment to permit different levels of conversation for different kinds of connections, telephone systems give a visual indication of what kind of connection has been made.

Topic
Personnel awareness
Applicable to
all

History

Priority
should
Dec 2021
When using cryptographic equipment to permit different levels of conversation for different kinds of connections, telephone systems give a visual indication of what kind of connection has been made.
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 permitting different levels of conversation for different kinds of connections shoulduse telephones that give a visual indication of what kind of connection has been made.
2010
Agencies permitting different levels of conversation for different kinds of connections should use telephonesthat give a visual indication of what kind of connection has been made.
2008
Agencies permitting different levels of conversation for different kinds of connections should use telephones that give a visual indication of what kind of connection has been made.