A record you can hold, and check yourself.
A record is a small, self-contained file. It checks signed commitments and included content under the recorded key. Compare that key or the record hash with a reference retained at sealing. The downloaded verifier works without this website; the recorded key alone does not identify who created the record.
How it works
Seal
A fresh key signs your file or note in your browser, then is discarded. Your data and key never leave the page.
Hold
You download one portable record that carries its own proof inside. The record is yours. You keep it.
Verify
Anyone checks it with the self-contained offline verifier. The downloaded verifier works without a network connection or account.
What verification establishes.
A passing check confirms the recorded data under its signing key. Identity, truth and completeness need separate evidence.
- The authenticated fields and included content agree with the signed commitments under the recorded key. Retain a separate expected key or record hash; changed content re-sealed under another key also verifies.
- Unsigned metadata is outside that guarantee. For a file record, check the original file against its recorded hash separately.
- The signed checkpoint contains a self-reported time. When the server timestamp signature verifies under a trusted time key and its commitment matches the sealed content, the sealed content (its hash) existed by that time. That timestamp is an Ed25519 signature from VerifyBundle’s own time service, not an accredited timestamping authority, and it does not cover the title, filename, private fields or key. Otherwise the time is self-reported.
- It was sealed by the holder of a signing key.
- That the data is true.
- Who the sealer is (the key is anonymous here).
- Physical presence, or that a real-world event happened.
- That nothing was left out.
- That it is legal evidence, notarized, or admissible in court.
Current hosted and offline verifiers refuse repeated JSON field names, invalid UTF-8 and excessive nesting. A passing check authenticates the fields covered by the signature; unsigned metadata remains outside that guarantee.
Uses for a retained record.
A record is useful anywhere you need to prove later that something is exactly what it was, without asking anyone to take your word for it.
Prove a file has not changed
Seal a contract draft, a design, a dataset, or a photo. Anyone holding the key or hash you gave them at sealing can confirm their copy is byte-for-byte the one you sealed, with no account and no trusted middleman.
Commit now, reveal later
Lock in a number, a decision, or a prediction. Put it in the sealed text. A verified, content-bound server timestamp can support a claim that the sealed content existed by then. A value kept in a private field is time-bound only if you handed the record over when you sealed it.
Share a record someone else can check
Give the recipient the record, the downloaded verifier and an expected key or hash through a trusted channel. They can check the record without connecting to this website.
Published format. Hybrid signatures.
A record sealed on this site carries a post-quantum hybrid seal: ML-DSA-65, a scheme standardized by NIST in FIPS 204, paired with Ed25519. Forging that seal under a record's key needs both schemes broken, so it stays sound as long as either does; ML-DSA-65 is believed to resist attack by a quantum computer. The time attestation is Ed25519 today. The verifiers also accept Ed25519-only (v1) records; the hosted verifier names which profile it checked, and the offline verifier does not yet. The construction is published: the specification and the conformance vectors are enough to re-implement the verifier.
- SHA-256 of your datathe fingerprint that detects any change, down to one byte
- Hybrid signatureML-DSA-65 + Ed25519, signed over the receipt (the README.txt in the file is not signed)
- Merkle checkpointbinds the elements included in the record; it does not prove that every relevant fact or event was included
- Public keyso anyone can check the signature, with no account
A file’s bytes stay with you: its hash goes into the record, along with its filename and title, in clear. (Sealed text is embedded, so a text record checks itself.)
VerifyBundle is built by Attested Intelligence, which publishes a signed decision-record format for AI agents (AGA, Attested Governance Artifacts). The two published formats share one construction, but they are separate: check an AGA evidence bundle with aga-verify or attestedintelligence.com/verify, not with this verifier, and aga-verify does not verify VerifyBundle records.
Seal a record now.
Create a record in your browser and download it for later verification.
Open the tool