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Orilami
The fingerprinted PDF will appear here once you encode it.

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Anti-Leak PDF

Anti-Leak PDF fingerprints a document uniquely for each recipient, so a leaked copy can be traced back to whoever received it. Every layer is written and read entirely in your browser — the file never leaves your device.

Layers written per document

  • Catalog: /Orilami /Payload — the 81-byte RS(81,49) codeword.
  • XMP: <orilami:payload> — the same codeword, base64.
  • Info dict: an Author hex tripwire plus zero-width bits (Hamming(15,11) SECDED) hidden in Subject.

How it works

The payload is 4 B magic + 1 B version + 16 B HMAC-SHA256 fingerprint + 24 B recipient id + 4 B timestamp, protected by shortened Reed-Solomon(255,223). Up to 16 corrupt bytes per surviving layer are recoverable, so the recipient can still be identified after cropping, re-compression, or a metadata purge that leaves any one layer intact.

FAQ

Is my PDF uploaded anywhere?
No — encoding and decoding run entirely in your browser. The file never leaves your device.
What if the leaker strips the metadata?
Each layer carries the payload independently, so the decoder recovers the recipient from whichever layer survives — Catalog, XMP, or the Info-dict fingerprint.
Do I need the same secret to decode?
Yes. The HMAC secret verifies authenticity and must match the one used to encode the document.
How much tampering can it survive?
The payload is protected by shortened Reed-Solomon(255,223) — up to 16 corrupt bytes per surviving layer are recoverable, so cropping and re-compression don't necessarily destroy the fingerprint.