Current safeguards
- Passwords are processed with PBKDF2 using SHA-256, an individual salt and repeated iterations. Plain-text passwords are not stored.
- Session tokens are stored as hashes and delivered through Secure, HTTP-only, SameSite cookies.
- Account-changing API requests are restricted to the same site origin.
- Email verification and password-reset codes are hashed, expire after ten minutes and enforce attempt limits.
- A successful password reset revokes existing sessions.
- Cloudflare provides the website, server-function and D1 database infrastructure.
Administrative access control
CloseBook uses role-based administrative access. Financial book content is not automatically available to every administrator. Authorized access requires the relevant permission and a documented reason, and sensitive access, export and modification operations are recorded for review.
Administrative book changes use revision checks, pre-change snapshots and audit records. Administrator changes do not automatically sign the book owner out; stale versions are rejected and must reload the latest cloud revision.
What security does not guarantee
No online service can guarantee absolute security, uninterrupted availability or recovery from every event. Browser extensions, malware, compromised email accounts, weak reused passwords, device loss, provider outages and user mistakes can still cause loss or unauthorized access.
Guest-mode limitations
Guest books are not protected by an account and are not synchronized. Anyone with access to the browser profile may be able to access them. Clearing browser data can destroy them permanently.
Registered-account limitations
Synchronization improves continuity between devices but is not an independent archival backup. Account access depends on the user's email account, password and the availability of the service and its providers.
User backup responsibility
- Export a full data backup after material changes and before deletion.
- Keep important closeout packages in a separate controlled location.
- Test that exported files can be opened and retained according to organizational policy.
- Do not treat CloseBook as the only copy of records required for tax, audit, legal or donor compliance.
Document files
CloseBook does not currently store invoice or receipt files. Users must maintain those files separately under their own retention and access-control process.
Reporting a security concern
Submit a Security report through the CloseBook support form. Do not include passwords, verification codes, reset codes or full sensitive financial records.