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Anyza Signature · free

Digital signature recorded on Bitcoin, for any file

Pick a file, write your message (name, acceptance, statement) and sign. The message is written inside the file itself, together with its fingerprint and the date recorded on Bitcoin. Anyone can check it here later — and get the original file back, intact.

  • Free
  • Your file never leaves your computer
  • Certificate inside the PDF
  • PDF, video, audio, image, Word

  • Date recorded on Bitcoin

Sign a file

How to sign

The file isn't uploaded: your browser computes the fingerprint and builds the signed file.

Check a signed file

Upload the signed file: we check here in the browser whether it's intact, show the message, the signer and the date on Bitcoin, and give you back the original.

The check recomputes the original's fingerprint, the seal code and (on level 3) the wallet signature, and verifies the proof on Bitcoin.

How it works

1

Pick the file and write

Any file up to 200 MB. Write who is signing and what you're stating — it goes along, forever.

2

The fingerprint is computed here

Your browser computes the file's SHA-256. Only that code, the message and the date go to the record.

3

Bitcoin record and signed file

The bundle is recorded on Bitcoin (OpenTimestamps) and you download the signed file. In a PDF, a certificate page with a QR code is added at the end.

Three signature levels

Stated name

You type your name. It proves the content and the date; the name is stated by the signer.

Anyza account

Signed with your Anyza account (verified email): the checker shows “signed by @user”, confirmed by Anyza.

Solana wallet

Your Solana wallet (Phantom, Solflare
) signs the message with its key — a cryptographic signature nobody can forge.

Important: the Anyza Signature proves the content, the date and (on levels 2 and 3) the account or wallet that signed. It is not a qualified e-signature (eIDAS / national PKI) — for documents the law requires that way, use the official certificate.

Frequently asked questions

What is the Anyza Signature?

It's a seal written inside the file itself with your message, the file's fingerprint and the date recorded on Bitcoin. Whoever receives the file checks here whether it's intact, who signed it and when.

Is it legally valid?

It's strong technical proof that the content existed on that date and wasn't changed, and it can be used as evidence. It's not a qualified signature (eIDAS, national PKI): when the law requires that kind of certificate, use the official one. We're not lawyers — if in doubt, ask one.

How is the signer proven?

It depends on the level. On level 1 the name is stated. On level 2 Anyza confirms it was your account (verified email). On level 3 your Solana wallet signs with its private key — only whoever holds the wallet can do it.

Do you see my file?

No. The file is read and signed in your browser. The server only receives the fingerprint, the message and the date to record on Bitcoin, and keeps just the seal code and the signature type — not even the message is stored.

What does the signed PDF look like?

Same as the original, plus one certificate page at the end (message, signer, date and a verification QR code). Everything is added as a PDF “update”, like official e-signatures: the original pages don't change, and a PDF that already had an official signature keeps it valid.

Does it work with video, audio and other files?

Yes. In images, videos, audio and others, the seal is written at the end of the file, which keeps opening normally. In Word, Excel and ZIP, it goes into the file comment, which also keeps opening. The checker separates the exact original file.

How much does it cost?

Nothing. It's free, with a daily limit to prevent abuse. The Anyza account is free too.

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