The skill and its purpose
Private content includes more than obvious personal names: client prices, unpublished artwork, location access notes and embedded document metadata can matter. Putting a file at an obscure address does not establish controlled access. OWASP recommends protecting private static resources as part of access control and using layered file handling controls. The public proof tool reads a selected file locally to calculate its digest; it does not upload that file, scan it for malware or certify it as safe to distribute.
Work through the decision
Classify the packet by purpose and intended audience. Inspect visible text, comments, hidden sheets, attachments and metadata using suitable software and competent review. Create a permitted distribution copy while retaining the source in its authorised location. Use the organisation’s commissioned sharing service and verify that access enforcement covers direct file retrieval as well as the page displaying the link. Confirm retention and deletion arrangements with the responsible owner. When a file must be processed by a provider, verify that route before transmission; a reassuring extension or filename alone does not validate its contents.
Practical exercise — fictional
In a fictional procurement comparison, a spreadsheet has a public supplier checklist on its first sheet, private prices on a hidden sheet and a personal phone number in a comment. Plan a clean technical packet for an installer without these unrelated fields. Use a dummy workbook or written mock-up rather than actual confidential data. Describe how you would check the exported copy, permitted recipient and service access behaviour. Keep a record of which source material was excluded and why; do not claim the resulting copy has undergone a full security assessment.
Take it to the next job
- Classify the purpose and intended audience.
- Inspect hidden content and metadata before sharing.
- Verify direct-file access in the chosen service.
- State which security checks were actually performed.
Try the decision
The exercise stays in this session unless you choose to save it.
