AnchoraDocument proof · Private pilot

Prove a document existed, exactly as it is.

  • Files are fingerprinted in your browser and never uploaded
  • Each fingerprint is recorded on a public blockchain
  • Anyone can check a document later with its QR code

Invite-only pilot. Your first three documents are free. Terms & privacy

Sign in

Welcome back. Use your Anchora account to continue.

Forgot your password?

Have an invite code? Create your account

Create your account

Your invite gives you 3 free documents to anchor.

At least 10 characters.

Already have an account? Sign in

Check your email

We sent you a link to confirm your address.

During the pilot, the person who invited you sends you the link.

Back to sign in

Confirming your email…

Sign in

Reset your password

Enter your email and we send you a link to choose a new password.

Back to sign in

Back to sign in

Choose a new password

You will be signed out on every device.

At least 10 characters.

AnchoraDocument proof
Dashboard Documents Account Help & FAQ

Documents left

– of your pilot allowance

Pilot member
Anchora Anchor document

Dashboard

Documents left

–

Free pilot allowance

Anchored

–

All documents

Final

–

100+ blocks deep

In progress

–

Queued or recording

Anchor a document

or drop them here

Each file becomes one anchored document and uses one credit. Files never leave this device.

    Recent documents

    View all

    Nothing anchored yet. Your first documents are free.

      Live status is unavailable right now; showing your documents without it.

      Document Anchored Status Block Details

      No documents match.

      Profile

      Email
      Member since
      Plan
      Private pilot
      Documents left

      Change password

      At least 10 characters. Other devices are signed out; this one stays signed in.

      Notifications

      Your data

      Download everything we hold about you: your account, document names, notes, tags, fingerprints and credit history.

      Need more documents? Ask the person who invited you; they can add credits to your account.

      Delete account

      This removes your email, password, document names, notes and tags, and ends every session. Fingerprints already on the blockchain stay there (they cannot be removed), but nothing links them to you any more. This cannot be undone.

      Back to documents Downloads are available once the document is written to the chain (about a minute).
      AnchoraProof of existence

      Certificate of record

      This certifies that the document below was recorded on a public blockchain at the time shown. Any copy whose fingerprint matches is exactly the same document, unchanged since then.

      Scan to verify

      How to verify

      1. Open the verify link or scan the QR code.
      2. Choose the original file (or every file of a bundle). It is fingerprinted on your device; nothing is uploaded.
      3. The page confirms whether the fingerprint matches this record, and how many blocks have been built on top of it.
      What does anchoring a document do?

      Your browser calculates the document's fingerprint (a SHA-256 hash): a 64-character code that changes completely if even one character of the file changes. Anchora records that fingerprint on a public blockchain with the time it was recorded. Later, anyone can recalculate the fingerprint from their copy and check that it matches the record.

      Is my document uploaded?

      No. The file is read in your browser and only the fingerprint is sent. The document's name is stored in your Anchora account so you can find it again; it never goes on the blockchain.

      What do Queued, Recording and Final mean?

      Queued: waiting for the next batch, usually under a minute. Recording: written to the blockchain and gaining confirmations. Final: 100 blocks have been built on top of the record, so it can no longer be undone. Until then a record can, in rare cases, disappear.

      How does someone else check my document?

      Share the document's QR code or verify link. The verify page shows whether that fingerprint was recorded and when. The other person can drop their copy of the file there to confirm it is exactly the same document.

      What if I anchor the same file twice?

      Nothing extra happens and no credit is used: Anchora recognises the same fingerprint and shows the existing record.

      What does "Secured" mean?

      After 10 blocks have been built on top of a record (about 20 minutes), it is practically permanent: undoing it would need a rival chain longer than the real one. It becomes Final at 100 blocks (about 3½ hours), the point after which the network cannot undo it at all.

      What is a bundle?

      Several files anchored together under one fingerprint, for example a contract with its annexes. It uses one credit. To verify a bundle, choose all of its files together on the verify page; changing, adding or leaving out any file gives a different fingerprint.

      What is the certificate for?

      Each document has a printable certificate of record with its fingerprint, time, blockchain transaction and a QR code to the verify page. Print it or save it as a PDF and keep it with the document or hand it to whoever needs to check it.

      Who can see my notes and tags?

      Only you. Notes, tags and document names stay in your Anchora account and never go on the blockchain. Read the privacy notice.

      I changed one word in the document. Is it still valid?

      No. A changed file has a different fingerprint, so it does not match the record. Anchor the new version as a separate document if you need proof of it too.