Question

A privacy engineer is reviewing a new mobile banking app that integrates with a third-party budgeting service via OAuth 2.0. Currently, the integration requests a broad scope granting full read access to all account transaction history and personal profile data, and the issued refresh tokens have no expiration. The budgeting feature only needs monthly spending categories. Which design change best applies privacy by design and data minimization to the authorization flow?

Accepted Answer

Restrict the requested OAuth scopes to only the aggregated spending-category data the feature needs, and set finite refresh-token lifetimes with re-consent on expiry

Answer

Keep the broad scope but encrypt the transaction data in transit using TLS 1.3 to protect it from interception

Answer

Continue issuing non-expiring refresh tokens but log all API calls the budgeting service makes for later audit

Answer

Require the user to accept an updated privacy notice describing the full-access scope before the integration is enabled