ASD ISM 1719 Colour code for TOP SECRET cables
What it says
TOP SECRET cables are coloured red.
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What it means
In plain EnglishTOP SECRET cables must be red to ensure easy identification and compliance.
This control is all about making sure cables that carry TOP SECRET information are easy to spot by colouring them red. This matters because if these cables aren't marked clearly, sensitive information might be mishandled or routed incorrectly, leading to potential security breaches.
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Why it matters
If TOP SECRET cables are not clearly identified as red, staff may mishandle them, increasing the likelihood of disclosure and serious security incidents.
How to implement
The IT team should survey the current infrastructure to identify all cables that handle TOP SECRET data.
They can do this by reviewing existing network diagrams and checking against data classification records.
Procurement should ensure that any new cable purchases meant for TOP SECRET data transmission are indeed red.
They can achieve this by specifying red cables in purchasing agreements and confirming with suppliers.
The facility manager should organise the relabelling of any existing TOP SECRET cables which are not red.
This can be done by using red cable sleeves or covers and documenting these changes for reference.
Security officers should train staff on recognising red cables as indicators of TOP SECRET data pathways.
This can be achieved by workshops or informational posters around data handling areas, emphasising the importance of the red cable protocol.
The IT infrastructure team should maintain an up-to-date inventory that marks which cables are carrying TOP SECRET data and ensure they are red.
This can be done using asset management software and regular physical checks.
Keep it running
Inspect cable colour during installs and quarterly checks. Ensure TOP SECRET cables are red; re-label or replace any non-red cables immediately.
Evidence and audit
- Check 1 of 5What an auditor asks for
Ask for
The current network cable inventory list.
Look at
Whether cables carrying TOP SECRET data are explicitly marked as red.
Good evidence
Shows a detailed list with all TOP SECRET cables noted as red, matching the infrastructure map.
- Check 2 of 5What an auditor asks for
Look at
The colour specification in recent orders and confirmations from suppliers.
Good evidence
Includes invoices and communications confirming red cables for TOP SECRET use.
- Check 3 of 5What an auditor asks for
Ask for
Training records related to security procedures about cable recognition.
Look at
Dates, attendee lists, and training content.
Good evidence
Provides records showing staff have been trained recently about the significance of red cables.
- Check 4 of 5What an auditor asks for
Ask for
To see the documentation of any re-labelling activities for existing cables.
Look at
Job completion records or work orders that detail what was relabelled and when.
Good evidence
Includes detailed records of actions taken and ensures compliance with the red cable requirement.
- Check 5 of 5What an auditor asks for
Look at
Whether red cables are correctly installed and labelled according to policy.
Good evidence
Confirms that all visible TOP SECRET cables are red and marked properly on-site.
Mappings
Closest match in ISO/IEC 27001: A.7.12, Secure cabling for power and data, which this control partially meets.
ISO/IEC 27001: 2 mappings
This control partially meets A.7.12.
ISM-1719 requires TOP SECRET cables to be coloured red so they can be rapidly and reliably identified as highly sensitive cabling. This supports Annex A 7.12 because clear visual identification assists correct physical handling and routing (e.g. segregation, heightened protection, prompt detection of misplacement), which reduces the likelihood of inadvertent exposure, interference or damage to sensitive cabling. Annex A 7.12 is about protecting cabling from interception/interference/damage overall, while ISM-1719 is a specific identification mechanism for one classification level rather than a complete cabling protection control.
This control supports A.5.12.
ISM-1719 requires a concrete classification-driven marking rule: TOP SECRET cables are coloured red to signal their sensitivity. This supports Annex A 5.12 because an effective information classification policy and practice typically needs implementable handling and identification conventions for classified assets, and ISM-1719 is one such convention applied to a specific asset type (cabling). Annex A 5.12 sets the organisational approach to classification across information and associated assets, whereas ISM-1719 does not define classification criteria and only prescribes one physical marking outcome.
Mappings show how controls relate across frameworks. They do not imply full equivalence or certification.