# Stamp an Object

The **vBase Stamper** records a file’s **timestamp**, **author**, and **digital fingerprint** (SHA3 hash) on a public blockchain. This metadata—known as [**provenance**](https://www.ibm.com/think/topics/data-provenance)—provides permanent, verifiable proof of a file’s authenticity and timestamp.

## How to Make a Stamp

For a quick overview, [🎥 Watch the How-to Video](https://www.youtube.com/watch?v=wRJCNvDkKR8)

#### Step-by-Step Instructions

1. Visit the [vBase App](https://app.vbase.com/)
2. Sign in or register for a free account
3. Go to the Stamper page: [app.vbase.com/stamp](https://app.vbase.com/stamp)
4. Click **“Browse for File”** and select your file
5. *(Optional)* Check the box if the file belongs to a **Collection**
6. *(Optional)* Select or create the relevant Collection
7. Click **“Make a Stamp”**

## What Happens When You Stamp a File

When you click **“Make a Stamp”**, the following process occurs:

* Your file’s **SHA3 hash** (also called the content ID) is calculated locally in your browser
* This hash is published to a [**public blockchain**](https://www.investopedia.com/terms/b/blockchain.asp), where it’s permanently recorded
* A **timestamp** is returned, reflecting when the blockchain included your content ID
* This becomes an **independently verifiable record** of your file’s existence and integrity

The following data is recorded to the blockchain:

* **Blockchain Address**: Your vBase account’s public blockchain address
* **Content ID**: The file’s SHA3 hash, serving as its unique digital fingerprint
* **Collection ID** *(if applicable)*: The identifier of the Collection the file belongs to

#### Example of a vBase Stamp

> * **Blockchain Address:** `0x0bf1504fB66c716161A8bc60906eC38792eA2000`
> * **Content ID:** `0x49adefb456c981ec67ab09b2b301b22a434922456169244e1f3b7e51d9fe54ee`
> * **Collection ID:** `0x9c22ff5f21f0b81b113e63f7db6da94fedef11b2119b4088b89664fb9a3cb658`
> * **Timestamp:** `2023-08-08 21:34:00+00:00`

**Note:** vBase does not publish or share your actual file, filename, or personal information on-chain. Only cryptographic identifiers are recorded to preserve privacy and ensure long-term verifiability.

## What Is a Collection?

A **Collection** groups related files—such as portfolios, observations, documents, data points, or project files—under a single identifier. When a file is stamped with a Collection, the blockchain record reflects that relationship, and this relationship itself becomes verifiable.

### Why Use Collections?

* 📦 **Dataset Integrity**: Prove a file was part of a specific group (e.g. a portfolio belongs to a particular strategy, or an observation belongs to a particular experiment)
* ✅ **Collection Verification**: Validate the completeness of a Collection. Using Collection stamping, you can assure a verifier that they're seeing all the data associated with a particular Collection, and no extra or missing data.
* 🧩 **Better Organization**: Track provenance across a project, experiment, strategy, or dataset

> 📌 **Tip:** Collections are optional. Files not in a collection are still independently verifiable.

## File Backups and Data Integrity

By default, vBase saves a **secure backup** of your file to help prevent data loss. You can enable or disable this setting in your [**Account Settings**](https://app.vbase.com/profile/#account_settings) under your profile.

**Important:** If backups are disabled, be sure to store your file safely. If the file is lost or changed, its provenance can no longer be verified.

## Quick FAQs

#### Can a Stamp Be Revoked?

No. Blockchain stamps are **permanent and immutable**. You can stamp a new version of a file, but existing stamps cannot be changed or deleted.

#### How Do I Verify a Stamped File Later?

You’ll need the **original file** and access to the blockchain record. Follow the guide here: [How to Verify a Stamped File](/web-tools/how-to-use-vbase-verify.md)

## Additional Notes

* Your file’s content ID (aka hash) is calculated **locally in your browser**. If backup is disabled, your file is **never uploaded** or seen by vBase
* [🔗 View a sample stamp](https://polygonscan.com/tx/0xe7dbb99c2f521a5c636d4cc7f6fd3c60cdf427c284230aa0093faac338b9d651) on Polygonscan
* Stamps are stored on the **Polygon blockchain** and can be independently verified using tools like [**Dune Analytics**](https://www.dune.com) or by querying Polygon nodes directly
* [🔒 SHA3](https://en.wikipedia.org/wiki/SHA-3) is a widely trusted cryptographic standard used in banking, telecom, and secure systems


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