---
{
  "title": "Confidentiality",
  "summary": "Limit information disclosure to the people and systems that should receive it.",
  "topic": "foundations",
  "level": "Beginner",
  "updated": "2026-10-12",
  "units": [
    1
  ],
  "aliases": [],
  "sources": [
    {
      "title": "NIST: An Introduction to Information Security",
      "url": "https://csrc.nist.gov/pubs/sp/800/12/r1/final"
    }
  ],
  "published": "2026-10-02",
  "editorialVersion": 2
}
---

## The idea

Confidentiality is protection against unauthorized disclosure. It applies to content and sometimes metadata, such as who communicated or when a record was accessed. Access controls, encryption, careful sharing, and appropriate handling all contribute. Consider the whole lifecycle, including exports, backups, logs, and disposal. A confidentiality rule should be tied to data ownership and a legitimate business or privacy requirement.

## In practice

A payroll report is restricted in its application, but an exported copy also needs controlled storage and sharing.

## A common misunderstanding

Protecting the main database does not preserve confidentiality if the same records appear in an unrestricted export or log.

## Check your understanding

What should a confidentiality review follow?

**Think it through:** Every place the information can be stored, used, transmitted, or copied.

## Follow a record through its copies

Consider a fictional recruitment company handling interview notes. The main application restricts notes to the hiring panel, but a recruiter downloads a spreadsheet, sends a summary to a manager, and includes a sample in a support ticket. Each copy creates another place where the original disclosure rule must be considered. The application permission is only one point in the information's lifecycle.

First identify what must remain confidential and from whom. Interview feedback may need a different audience from interview scheduling information. Metadata can matter too: revealing that a person is interviewing may be sensitive even when the feedback itself is hidden. A precise requirement makes control choices easier to justify than declaring every document equally secret.

Encryption helps protect information in particular storage or transport situations, but an authorized recipient can still copy or misdirect readable content. Access reviews, sharing restrictions, retention, and disposal therefore remain relevant. The control should match the realistic disclosure path rather than assuming encrypted storage resolves every confidentiality concern.

## Build a disclosure map

For the recruitment example, draw the original record and its spreadsheet, email, backup, and support copies. Beside each, write its intended audience, owner, retention need, and deletion method. Use fictional names and notes so the exercise does not create a real confidentiality problem.

Then consider a mistaken recipient. Who can revoke a link, determine what was accessed, and assess the consequence? A shared link and an attached file have different recovery properties. The exercise shows why confidentiality is not simply a password on a database. It is a defined disclosure rule maintained across the places where people and systems actually use the information, with a practical response when that rule is broken.

## Keep exploring

- [[cia-triad]]
- [[data-classification]]
- [[cryptography]]