PAdES
PAdES, short for PDF Advanced Electronic Signatures, is a standard from ETSI for putting digital signatures inside a PDF so that any reader can check the file is unchanged.
In plain words
A PDF can carry a digital signature in its own structure. PAdES says exactly how, so different readers agree on what they see. It is defined in ETSI EN 319 142-1 and has four baseline levels: B-B, B-T, B-LT and B-LTA. Each adds something to the one before.
- B-B has the signature and the signing certificate.
- B-T adds a trusted timestamp.
- B-LT embeds the certificates and revocation data, so the file can be checked on its own.
- B-LTA adds a document timestamp over everything, so it can stay checkable as certificates and algorithms age.
Our guide What is PAdES? explains each level in more depth.
An example
A sealed lease is opened five years later. The reader finds the PAdES signature, recomputes the hash and compares it with the signed value. It then reads the timestamp to see when the seal was made. If the file has been edited since, the check fails.
How it shows up in docuinked
docuinked applies one PAdES seal to each finished document, after the last signer. The seal carries an RFC 3161 timestamp from an outside authority. That is the B-T level. We don't yet embed the full validation data for B-LT.
Our seal certificate is our own and not on the Adobe trust list yet. So Acrobat reports the signer as unknown. The integrity check still works, and you can test any file with the free checker.
Common confusions
PAdES is a format, not a legal level. Under eIDAS, "advanced" and "qualified" are legal terms. A PAdES file can hold a simple, advanced or qualified signature. The word "Advanced" in the name doesn't make a signature advanced in law.
One seal, many signers. People expect one PAdES signature per signer. docuinked seals once at the end instead. People sign on the page, and the seal protects the result.
Related terms
Sources
Checked 2026-11-07.
Common questions
Which PAdES level does docuinked produce?
B-T: a PAdES signature plus an outside timestamp. B-LT, with embedded validation data, is not in place yet.
Is PAdES only for Europe?
No. It is a technical standard published by a European body, but any PDF reader can check it. US documents use it too.
Can I see the PAdES seal in a normal PDF reader?
Yes. Most desktop readers show a signature panel listing the seal, its time and whether the file has changed. Some phone viewers don't show signatures at all.
Related
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