§ SECURITY & PRIVACY

Security & Privacy

Blackbar is a tool for not leaking secrets. It would be absurd if the tool itself leaked them — so here is exactly how it handles your data, and how to verify what you download.

Offline by design

Everything — OCR, detection, and redaction — runs locally on your machine. Blackbar has no account, no sign-in, and sends nothing anywhere.

macOS: the app ships with no outgoing-network entitlement. An automated test in CI asserts it, so the binary cannot open a network connection.
Linux: the AppImage bundles its OCR models and fonts inside the package and opens no sockets — nothing is fetched at runtime.
No telemetry, no analytics, no crash reporting. There is nothing to opt out of because there is nothing collected.

This is what makes Blackbar easy to approve on sensitive or air-gapped machines: there is no data flow to review.

Redaction that can't be undone

A black rectangle drawn over a secret still has the secret underneath; a blur can be reversed on short strings; and the file often still carries EXIF/GPS/XMP metadata. Blackbar avoids all three:

Exports are re-encoded into a fresh opaque bitmap with the redacted regions overwritten — no hidden layer, nothing recoverable underneath.
All metadata is stripped on export (EXIF, XMP, IPTC, GPS, thumbnails). A test reads exported files back and asserts the original content and metadata are gone.
Blur and pixelate are flagged reversible and are never applied to a detected secret without an explicit confirmation.

Verify your download

Every release is published with a SHA-256 manifest and a GPG signature, so you can confirm your download is intact and really came from us.

Files: SHASUMS256.txt · SHASUMS256.txt.asc · public key

# 1. check the file hash matches the manifest
shasum -a 256 -c SHASUMS256.txt        # macOS / Linux

# 2. verify the manifest was signed by Blackbar
gpg --import blackbar-signing-key.asc
gpg --verify SHASUMS256.txt.asc SHASUMS256.txt

Expect Good signature from "Blackbar Release Signing". The signing key fingerprint is:

69DF BA36 B149 7CE8 45A0 0091 4779 4781 CF58 7E79

Build & platform integrity

macOS — signed with an Apple Developer ID and notarized + stapled by Apple, so Gatekeeper verifies it on first launch.
Linux — the AppImage and .deb are covered by the signed SHA-256 manifest above (Linux has no OS-level gatekeeper, so the checksum + GPG signature are how you verify provenance).
Downloads are served over HTTPS from dl.getblackbar.com.

Licensing, without a server

Your license is a small Ed25519-signed token verified entirely on your machine — there is no activation call and no license server to phone home to. The same code activates macOS and Linux. Purchases are handled by Stripe; we never see or store your card details.

Reporting a vulnerability

Found a security issue? Please email [email protected] — see our security.txt. We aim to acknowledge within 72 hours and will credit reporters who want it. Please don't disclose publicly until we've had a chance to fix and ship.