---
title: "How proof works"
description: "What Sureshake records and anchors on Base, what an anchor proves, and what it does not."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.sureshake.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How proof works

Read this page to work out what a Sureshake anchor tells you before you rely on it. In short, an anchor proves that a fingerprint existed by a certain time. It doesn't prove that what the fingerprint stands for is true.

## Fingerprints

A fingerprint is a SHA-256 hash, a short value calculated from a piece of data. The same data always gives the same fingerprint, and any change to the data gives a different one. You can't work back from a fingerprint to the data.

Anchoring means publishing a fingerprint on Base, a public blockchain, where the time it appeared can't be changed later.

## What Sureshake anchors

| Record                | What goes on Base                                           | Who owns or writes it                            |
| --------------------- | ----------------------------------------------------------- | ------------------------------------------------ |
| **Attested events**   | One combined fingerprint for each hourly batch              | Written by Sureshake                             |
| **Minted reports**    | A token holding a hash or content ID, and a metadata link   | Owned by the report's owner                      |
| **Locked forecasts**  | A token holding the forecast's hash                         | Owned by the company or person who made the call |
| **Reputation grades** | The company's grade, recorded against its on-chain identity | Written by Sureshake                             |

**Attested events** are histories of what happened to a document. There are two kinds today:

- A connected system, such as Test and Accept, reports a statement of work being signed, an acceptance criterion or milestone being accepted, a test run passing, an invoice being paid or a change order being signed.
- Sureshake itself records a recipient accepting an NDA on a shared report.

Each event names the event before it for the same document, so the history has a fixed order. To check one, see [Verify an attestation](/trust/verify-attestations/).

**Minted reports** carry a **View on BaseScan** link in their version history. A minted report is locked. The `/verify` page covers attested events only, so use the BaseScan link to check a minted report's token.

**Reputation grades** are covered in [Reputation](/trust/reputation/).

## What stays off the blockchain

Documents, report contents, financial figures, names and email addresses are not published on Base.

> **Metadata on IPFS is public**
>
> Minting publishes metadata to IPFS, a public file network, and it includes the
> report's title and description. Reputation events publish metadata there too,
> including the company's five component scores. You can't remove published
> metadata, so check a report's title and description before you mint it.

## What an anchor proves

If an attested event checks out, you know:

- **Existence by a time.** That fingerprint was published no later than the time of the block it was anchored in.
- **No later changes.** Anyone holding the original document can recalculate its fingerprint and compare. A changed document won't match.
- **The recorded order.** The event sits at that position in the document's history, as the submitting system reported it.
- **Who anchored it.** Only an account with the attester role on the registry contract can anchor a batch, and batches run in strict sequence.

## What an anchor does not prove

- **That the content is true.** A fingerprint of a wrong figure is still a valid fingerprint. Reported figures are the reporter's own.
- **That the event happened.** An attested event shows that a system reported it. That report rests on the system and the people using it.
- **When the event happened.** The event's stated time comes from the system that submitted it. The anchor only sets the latest time it can have been recorded.
- **That the history is complete.** Sureshake can only anchor what was submitted. An event that was never reported leaves no trace.
- **That a report token came through Sureshake.** The report token contract lets any wallet mint a token with any hash, so a token found on its own shows nothing. Start from the **View on BaseScan** link on the report in Sureshake.
- **Who a person is.** The name on an NDA acceptance is what the signer typed, and the email comes from their signed-in account. Neither is an identity check.
- **Quality, solvency or legal effect.** An anchor is not an audit, a credit opinion or legal advice.

Sureshake also chooses what goes into each batch. If you need more assurance about an event, ask the parties or the source system.

## What a Verified badge means

A **Verified** badge on a company refers to Sureshake's verification of that company. It doesn't apply to the company's reports, figures or job listings.

## If Sureshake is unavailable

Anchors stay on Base regardless of Sureshake. The proof that connects an event to its anchor comes from Sureshake's API, so save a copy if you may need it later. See [check a saved record](/trust/verify-attestations/#check-a-saved-record).

Source: https://docs.sureshake.com/trust/how-proof-works/index.mdx