Create a verifiable record of a file or note.
Seal it in your browser, keep the record, and check it later. No account is required. Your file or note stays on your device during sealing and verification.
How the record works
A new key pair signs each record in your browser using ML-DSA-65 and Ed25519. SHA-256 commits to the content. Online sealing sends a blinded commitment to our time service; its signed time is a statement from our service, not an independent time authority. The record does not establish who created the content.
Check content against its signed record. Verification does not establish authorship, truth or a trusted creation date.
FreeNo accountOffline verificationYou keep the record
What you get
A portable record you can check.
A record contains signed commitments to a file or note. Verify its structure and included content under the recorded key, then compare it with the key or record hash you retained separately. For a file record, keep the original file too: it is not embedded in the record.
- DataPublic sample note
- SHA-256918492be4f…4b7cf1
- Merkle rootb4ffcc4005…a08910
- SignatureML-DSA-65 + Ed25519 · under the fixture's recorded key
- Checkpointsigned · verified offline
These fields come from the published sample record. Its integrity checks under the recorded key; this does not independently identify its author or verify its time.
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.
A passing check establishes consistency under the record's key. It does not establish authorship, truthful claims or complete capture. Retain a separate expected key or record hash to identify the record you intended to check. What a record is, in full.