Using Cryptographic Sanitisation on Mobile Devices
Ensures cryptographic keys are erased on SECRET or TOP SECRET devices in emergencies.
Plain language
If you have a mobile device that contains highly sensitive information, like national security secrets, it’s vital to be able to quickly erase encryption keys in an emergency. This is important because keeping these keys on the device means someone could unlock and access that sensitive information if they got their hands on it.
Framework
ASD Information Security Manual (ISM)
Control effect
Responsive
Classifications
S, TS
ISM last updated
Nov 2021
Control Stack last updated
19 Mar 2026
E8 maturity levels
N/A
Guideline
Guidelines for enterprise mobilitySection
Mobile device usageOfficial control statement
If a cryptographic zeroise or sanitise function is provided for cryptographic keys on a SECRET or TOP SECRET mobile device, the function is used as part of mobile device emergency sanitisation processes and procedures.
Why it matters
Failing to zeroise keys swiftly can expose SECRET/TOP SECRET data if a mobile device is lost or stolen, risking national security.
Operational notes
Regularly test the cryptographic zeroise/sanitise function on the device and ensure it is embedded in emergency sanitisation procedures for rapid use.
Implementation tips
- Managers responsible for mobile devices should identify which devices hold SECRET or TOP SECRET information. They should make a list of these devices and regularly update it to ensure all are accounted for.
- The IT team should enable cryptographic zeroise or sanitisation functions on applicable devices. This means setting up the devices so that, in an emergency, these functions can quickly erase the cryptographic keys.
- IT security staff should develop and document an emergency procedure for using the zeroise or sanitisation function. This includes instructions on when and how to use it, and who is authorised to conduct this action in various scenarios.
- Training personnel who handle SECRET or TOP SECRET devices is crucial. The IT team should conduct practice sessions where employees learn to engage the emergency cryptographic functions, so they are prepared to act quickly if needed.
- Managers should regularly review these procedures and update them as technology or organisation needs change. Scheduling a semi-annual review can ensure that the processes remain relevant and effective.
Audit / evidence tips
- AskThe list of all devices classified as SECRET or TOP SECRET: It should be regularly updated GoodShows a clear, current list with appropriate sign-offs
- GoodProvides easy-to-understand proof of these settings being utilised
- AskTo see the emergency procedure documentation: Verify that it includes steps for activating the cryptographic sanitisation. Check that the names of authorised individuals and conditions under which this should be performed are listed GoodOutlines clear, concise steps with designated responsible personnel
- GoodIncludes a comprehensive training schedule with attendee lists and feedback
- GoodIs a calendar or log showing future and past review dates, with improvement actions noted if necessary
Cross-framework mappings
How ISM-0702 relates to controls across ISO/IEC 27001, ISO/IEC 42001, Essential Eight, and ASD ISM.
ISO 27001
| Control | Notes | Details |
|---|---|---|
| sync_alt Partially overlaps (1) expand_less | ||
| Annex A 8.24 | Annex A 8.24 requires defined and implemented rules for cryptography and cryptographic key management across their lifecycle, including s... | |
These mappings show relationships between controls across frameworks. They do not imply full equivalence or certification.