Question 1

Does this prove the document is mine?

Accepted Answer

It proves the document existed in this exact form at the timestamp you signed, and that the holder of the private key (presumably you) signed off on it. It does not prove authorship without an independent identity claim.

Question 2

Why hash instead of sign the document directly?

Accepted Answer

Privacy and size. The hash is small and reveals nothing about the contents. You can publish the certificate without disclosing the document — only the holder of the original can later prove the match.

Question 3

How tamper-evident is the timestamp?

Accepted Answer

The timestamp inside the signature is what you claimed. For independent timestamps, post the certificate to a public Bitcoin transaction, OpenTimestamps, or a notary service that publishes a verifiable log.

Question 4

What hash function does Notary use?

Accepted Answer

SHA-256. The certificate also embeds the file size and a short filename hint to make later verification more user-friendly.

Question 5

Can I notarize a folder or multiple files?

Accepted Answer

Hash and notarize each file individually, then sign a manifest listing all the per-file hashes. The Utilities tool can produce SHA-256 sums in bulk.

Notario