Proovik
Certify
Simple process

How It Works

Prove that your document already existed at a specific date and time. Four steps, without uploading the file.

Four steps, from start to finish

A simple and transparent process to timestamp your documents

  1. Select your document

    Drag or select any file. Your document never leaves your device.

    • PDF
    • DOCX
    • JPG/PNG
    • ZIP

  2. We generate the hash

    We calculate the SHA-256 of your file locally. It's like a unique "fingerprint".

    SHA-256 0f7383b381366cc3a75dadd7e4a1e8998c492f7c5c5610f4384d7320f484aad8
    Real example · 2026-09-20

  3. Register on Kaspa

    The hash is inscribed in a Kaspa blockchain transaction with timestamp.

    Kaspa mainnet

  4. PDF Certificate

    Download your certificate with hash, TX ID, timestamp and verification data.

What does the certificate contain?

SHA-256 hash of the document

SHA-256

Kaspa transaction ID

Kaspa TX ID

Exact timestamp

UTC Timestamp

Merkle Proof for verification

Merkle Tree

Anyone can check it, without asking us

The certificate contains everything needed to repeat the check with standard tools: recompute the document's SHA-256, follow the Merkle path and find the transaction on the public Kaspa network. No account, no API of ours, and no need for Proovik to still exist.

How to verify a proof
PVK-PROOF/1

Ready to certify your first document?

It's free, instant and requires no registration.

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