Timestamp a File

This guide walks you through timestamping a file with Veristamp.

Step 1: Open Veristamp

Go to stamp.veristamp.in in your browser.

Step 2: Select your file

Drag and drop a file onto the dropzone, or click to open the file picker. The file is never uploaded — hashing happens entirely in your browser using the Web Crypto API.

Note

Only the hash is submitted for timestamping. Filename and size are optional metadata, not proof material.

Step 3: Review the hash

Once the file is selected, Veristamp displays:

• Algorithm: SHA-256
• Hash: The hex-encoded digest of your file

You can independently verify this hash using any SHA-256 tool:

bash

$ sha256sum yourfile.pdf e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855  yourfile.pdf

Step 4: Submit for timestamping

Click Timestamp. The browser sends only the hash (not the file) to the Veristamp signing service:

HTTP Request

POST /api/v1/timestamp Content-Type: application/json
{ "hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", "filename": "yourfile.pdf", "size": 12345 }

The signing service responds with a signed receipt.

Step 5: Save your receipt

The receipt is a JSON file. Save it alongside the original file. The receipt contains everything needed for offline verification:

{
  "receipt_id": "vst_r_7f3a2b1c",
  "issuer": "Veristamp",
  "issued_at": "2026-06-05T12:00:00Z",
  "key_id": "vst_sign_2026_q2_01",
  "algorithm": "SHA-256",
  "hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  "nonce": "xK9mP2vL8nQ4wR7j",
  "signature": "aBcDeFgHiJkLmNoPqRsTuVwXyZ..."
}

Keep both files

The receipt proves the timestamp, but verification also needs the original file so its SHA-256 hash can be recomputed.

What happens next

Within 24 hours, your receipt is sealed into a public, append-only Merkle log. This makes it cryptographically tamper-proof and publicly auditable. You don't need to do anything — the receipt already contains proof of submission, and the transparency log is independently verifiable by anyone.