How it works

Time-stamped proof of existence for your files

Is creating or checking a fingerprint free?

Yes. Generating a fingerprint (SHA-256 hash) and checking whether a document matches a stored fingerprint are both completely free. You only pay if you want to publish a fingerprint to the blockchain.

Can I double-check the hash that's calculated for me?

Yes, and we encourage it. The fingerprint we generate is a standard SHA-256 hash, widely used in finance, cybersecurity, digital signatures, and legal archiving.

You can independently check and re-calculate this hash using hash tools available on most systems:

There are also open-source GUI tools like GtkHash (Linux/Windows) and HashCheck (Windows) that let you verify hashes visually.

The hash must match exactly — if even a single character is different, the file has changed. This is why SHA-256 is trusted for legal and compliance use worldwide.

How do I know my data stays private and secure?

Your file never leaves your device. The SHA-256 fingerprint is calculated entirely in your browser using client-side JavaScript. Only the resulting hash — a short string of letters and numbers — is sent to our server and stored on the blockchain.

Our application has no upload buttons, no file transfer forms, and no backend endpoints that accept files. You can verify this by opening your browser’s developer tools and inspecting the network activity during fingerprint creation.

This setup guarantees that your data stays private and never reaches us — which also makes the service GDPR-compliant by design.

How is the fingerprint published to the blockchain?

We developed custom software that interacts directly with the Solana blockchain. When you publish a fingerprint through our tool, our backend initiates a micropayment transaction from our blockchain address MintbvtvVA7u5yMPcVhLuywdVcrq4ERSo3o2z8Ww8sq. You don’t need a crypto wallet or blockchain knowledge — we handle the technical side entirely.

If you’re curious, you can paste our Solana address into the official Solana Explorer at explorer.solana.com to view all transactions ever made from our address.

How do I pay?

You can pay securely using credit card, iDEAL, or bank transfer. Payments are handled by Mollie, a licensed European payment provider. After payment of 4.95 euro, you’ll receive an invoice and token by email. The token lets you publish up to 50 fingerprints within 60 days — across as many sessions as you like. No subscription. No crypto wallet needed.

Can someone fake the timestamp?

No, the timestamp is not generated by us. It comes directly from the Solana blockchain, where your hash is permanently stored. Each transaction includes an immutable time marker, issued and validated by the decentralized Solana network.

This means you can't backdate or alter the proof and neither can we.