Document Notary

Verify a document

Prove a file existed, unmodified, at a point in time. Verification runs entirely in your browser — no account, no upload, no trust in us required.

1 · The document

Drop the file here, or click to choose. It is hashed locally and never uploaded.

2 · The receipt

Drop the .ots receipt here, or click to choose.

Why you can trust the result: the verdict comes from mathematics, not from us. The receipt chains your document's SHA-256 fingerprint to Bitcoin's public ledger; any OpenTimestamps tool reaches the same conclusion. Read how it works on the Document Notary page.

Check a Keepsake download

Every release is published with a manifest listing each file's SHA-256, signed by a key that never touches this web server. Drop an installer or .apk below to check it against that manifest.

Drop Keepsake-win-Setup.exe or the .apk here. Hashed locally; nothing is uploaded.

Be clear about what this proves. This page is served by the same host as the download, so if that host were compromised it could serve you a bad file and a page that blesses it. This check is a convenience, not a proof.

The check that does not depend on us: run Keepsake.exe --verify <file> from a copy of Keepsake you already had installed. It carries the release public key inside it and was on your machine before this download existed, so it is a genuinely independent opinion. The key is also printed on the security page — note it down once and you can check any future release against it by hand.

Last verified 3 September 2026 — by bash tools/verify-portal.sh https://securekeepsake.com. Every claim on this site is listed, with its evidence, in the claim ledger.