ASD ISM 1116 Ensure separation between TOP SECRET and other cabinets
What it says
A visible gap exists between TOP SECRET cabinets and non-TOP SECRET cabinets.
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What it means
In plain EnglishEnsure there's a visible gap between top secret and other cabinets for security reasons.
This control is about keeping top-secret information separate from other confidential information by physically separating their storage cabinets. This matters because if all your sensitive papers are stored together, there's a higher risk of someone accessing information they shouldn't, which could lead to leaks or misuse of critically sensitive data.
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Why it matters
If TOP SECRET and non‑TOP SECRET cabinets are not visibly separated, staff may misfile items, causing improper storage, spillage and potential compromise of TOP SECRET holdings.
How to implement
Facility manager should identify the physical locations of top-secret and other cabinets.
Use a tape measure to ensure there's a noticeable gap of at least one metre between them to make sure they are distinctly separate.
Office manager should label the cabinets appropriately.
Clearly mark the top-secret cabinets as such to reduce confusion about which cabinets contain which level of information.
Security personnel should ensure the physical layout supports separation.
Conduct a walkthrough to confirm that the gap is present at any time, and consider adding physical barriers if needed.
IT manager should document the layout and any changes in a secure record.
Keep a floor plan that shows the position and separation of each cabinet stored in a secure digital file and update it whenever changes happen.
Staff responsible for the documents within the cabinets should undergo training.
Understanding why this separation is important can reinforce the importance of maintaining these physical barriers.
Keep it running
Maintain a clearly visible gap between TOP SECRET and other cabinets; label TOP SECRET storage prominently and confirm the gap remains during routine physical security checks.
Evidence and audit
- Check 1 of 5What an auditor asks for
Ask for
The facility layout plan showing cabinet locations: Request a copy of the site's current floor plan.
Look at
The plan to ensure there's a clear separation marked between top-secret and other cabinets.
Good evidence
Will show a minimum one metre gap clearly marked on the plan.
- Check 2 of 5What an auditor asks for
Ask for
Photographs or videos of the cabinet setup: Request recent media that depicts the cabinets' actual locations.
Look at
These images to verify the separation.
Good evidence
Will show that the cabinets are not only separated, but that the separation is easily visible.
- Check 3 of 5What an auditor asks for
Ask for
To see the training records of responsible staff: Request documentation of training sessions describing the separation requirement.
Look at
Names, dates, and content relevance.
Good evidence
Includes regular training that discusses physical security requirements.
- Check 4 of 5What an auditor asks for
Ask for
About incident reporting for breaches or concerns: Request logs or records of any issues reported regarding cabinet separation.
Look at
How incidents were noted and resolved.
Good evidence
Will list resolved issues and any preventive actions taken.
- Check 5 of 5What an auditor asks for
Ask for
The security policy document covering cabinet setup: Request the part of the security policy that outlines cabinet separation.
Look at
Detailed instructions on space requirements.
Good evidence
Includes clear guidance for maintaining these processes.
Mappings
Closest match in ISO/IEC 27001: A.7.5, Protecting against physical and environmental threats, which this control partially meets.
ISO/IEC 27001: 2 mappings
This control partially meets A.7.5.
Annex A 7.5 requires organisations to design and implement measures that protect physical infrastructure from threats, including preventing compromise through physical proximity or interference. ISM-1116 requires a visible gap between TOP SECRET and non-TOP SECRET cabinets, reducing accidental cross-access, tampering opportunities and handling errors in physical environments. Annex A 7.5 is broader because it applies across classifications and also includes environmental threat protection (e.g. fire, water, smoke, heat).
This control partially meets A.7.8.
ISM-1116 requires organisations to maintain a visible physical gap between TOP SECRET cabinets and non-TOP SECRET cabinets to reduce the likelihood of mix-ups, unauthorised access, or inadvertent disclosure. This relates to Annex A 7.8 because securely siting and protecting equipment includes ensuring security containers (and their placement) are arranged to prevent compromise and support safe handling. Annex A 7.8 is broader, covering secure placement/protection of equipment generally, whereas ISM-1116 prescribes a very specific physical separation measure for TOP SECRET storage.
Mappings show how controls relate across frameworks. They do not imply full equivalence or certification.