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TimeCairn

How it works

Stake a file in five steps. Keep the evidence needed to verify it.

  1. 01

    You upload a file.

    A draft, a sketch, a paper, a CAD file, a notebook page, a piece of source code — anything you want to claim priority on. Up to 50 MB at v1. The bytes you upload are exactly what gets witnessed.

  2. 02

    The registry hashes the file.

    SHA-256 over the bytes produces a 64-character digest, also called a fingerprint. It is designed to make finding different files with the same digest impractical. The registry stores the digest; the file content is never sent anywhere except the storage you authorized.

  3. 03

    Multiple Time Stamp Authorities witness the fingerprint.

    The fingerprint is sent to several independent Time Stamp Authorities (TSAs) — public services run by certificate authorities like FreeTSA, DigiCert, Sectigo, GlobalSign. Each TSA signs the fingerprint with its private key and a time value under its published policy. This uses RFC 3161 — a standard for timestamping a digest. Each returned token records a time and a signed response to that digest. The receipt does not itself decide ownership or legal priority.

    Keep the responses and certificate material shown in your receipt.

  4. 04

    You get a receipt page.

    A public URL with the file fingerprint, the timestamp from each witness, downloadable proof tokens (one .tsr file per witness), and the exact openssl ts -verify command anyone can run. The receipt is yours. You can share the URL, embed it in a patent disclosure, cite it in a journal, or hand it to a court.

  5. 05

    Verify offline with the saved evidence.

    Download the original file, the witness .tsr token, and the witnessing TSA's public CA certificate. Run:

    openssl ts -verify \
  -data <your-file> \
  -in <witness>.tsr \
  -CAfile <tsa-cacert>.pem

    Successful output: Verification: OK. Save the file, token, and appropriate certificate chain. Verification depends on those materials and the trust policy you apply; a successful cryptographic check does not determine legal weight.

Why multiple witnesses

Each successful timestamp response adds a signed record for the same digest. If one response becomes unavailable or untrusted, the other responses can still be assessed independently. Check each response against its certificate material and trust policy. The number of witnesses does not by itself determine legal weight.

Privacy options

Choose your delivery option before submitting. Without a saved preference, the form starts with Public + download, which uploads the file to publicly readable storage. Hash-only + download computes the digest in your browser and sends the digest and supplied metadata instead of the file bytes. Receipt publication is a separate setting: new receipt records start private. A private receipt does not make a file uploaded to public storage private. Keep the original file and downloaded proof material for verification.

Stake your first file