What the redaction certificate proves

Omitly’s certificate is a precise instrument. It is worth being exact about what it does and does not tell a recipient, because overstating it would be worse than saying nothing.

The short version

Tamper-evident proof that the redacted content is absent from this document — not a determination of legal compliance, and not a claim about your other copies or backups.

What it proves

• The redacted content is not present in the output document. The audit report records each region and the result of Omitly’s own check that nothing recoverable remained inside it.
• The file has not been altered since it was sealed. The seal is computed over the exact bytes of the delivered PDF — the visible content and the embedded report together. A single changed byte makes the seal fail on verification.
• Which source it came from, if you ask. Supply the original and Omitly confirms the recorded input hash matches, tying the redacted file to that exact document.

What it does not prove

• It is integrity, not identity. The signing key is generated on the machine that sealed the file and never leaves it. A valid seal tells you the file is unchanged since Omitly sealed it — it does not, on its own, tell you who operated Omitly. Omitly shows the key’s fingerprint so you can compare it out of band when origin matters.
• It is about one file, not your whole record-keeping. It says the redacted content is absent from this output document. It is not a claim about other copies, drafts, email or backups you hold elsewhere.
• It is not a legal determination. The certificate is a technical artifact. It does not decide whether you have met a particular legal or regulatory obligation — that remains your responsibility and, where relevant, your lawyer’s.

Why the honesty is the point

Anyone can draw a black box and call a document redacted. The certificate is useful precisely because it claims something narrow that is actually checkable: the content is gone from this file, and the file is unchanged since. A recipient can confirm both on their own machine. See How to verify a redacted PDF.