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Cover image for Turn Any Webpage into Verifiable Evidence
Christian Ahrweiler
Christian Ahrweiler

Posted on Originally published at Medium

Turn Any Webpage into Verifiable Evidence

Turn Any Webpage into Verifiable EvidenceWebpages are temporary.

An online offer can be changed. A product description can disappear. A customer portal may show different information tomorrow. Prices, terms, order details and public statements can all be updated without leaving a visible history.

A normal screenshot captures what was displayed — but it does not prove when the screenshot was created or whether the file was modified afterward.

Beaver Page Proof is designed to provide a stronger, independently verifiable record of a webpage.

More Than a Screenshot

Beaver Page Proof is a focused browser for macOS. Open a webpage, sign in if necessary and select Create Page Proof.

The app records several complementary representations of the current page:

  • A full-page PNG screenshot
  • A PDF representation
  • A WebKit web archive
  • The rendered HTML
  • The visible page text
  • The final URL, title, capture time and technical metadata
  • A SHA-256 manifest covering every evidence file These files are combined into a completed evidence archive:

Beaver-Page-Proof.zip

Once created, this inner archive is no longer modified.

Independently Timestamped

Beaver calculates a cryptographic hash of the completed evidence ZIP and submits a protected commitment to public OpenTimestamps calendars.

The screenshot, webpage, URL and ZIP are never uploaded to OpenTimestamps. Only an opaque cryptographic commitment is submitted.

OpenTimestamps collects many requests and combines them into a Merkle tree. The resulting root is anchored in a Bitcoin transaction, allowing thousands of documents to share the cost of a single blockchain entry.

Beaver remains open while this process is completed.

The wait may take several hours — and that is intentional. The app is not simply writing the current time into a local text file. It is waiting for independent confirmation that the evidence archive has been anchored in the Bitcoin blockchain.

One Package to Share

After confirmation, Beaver creates one final delivery ZIP containing:

  • Beaver-Page-Proof.zip
  • Beaver-Page-Proof.ots
  • Timestamp-Report.txt
  • Verify-Proof.txt This package can be sent to a customer, business partner, lawyer or anyone else who needs to inspect the recorded state of the webpage.

The recipient does not need Beaver Page Proof and does not need an account.

To verify the package:

  • Extract the delivery ZIP.
  • Open opentimestamps.org.
  • Drop Beaver-Page-Proof.ots onto the verification area.
  • Select Beaver-Page-Proof.zip when requested. OpenTimestamps then verifies whether the exact evidence ZIP matches the blockchain timestamp.

Changing even one byte invalidates the proof.

Useful Wherever Online Content Can Change

Beaver Page Proof is not built for one particular website or marketplace. It is a generic solution for documenting online content, including:

  • Online offers and product descriptions
  • Prices and availability
  • Order and booking details
  • Customer portals
  • Terms and conditions
  • Public announcements
  • Account information
  • Support conversations
  • Published articles
  • Administrative pages
  • Personalized content visible after login Because the page is opened inside the integrated browser, Beaver can also record content that is not publicly accessible — provided the website permits login inside an embedded browser.

What the Proof Establishes

A successfully verified package demonstrates two important facts:

  • The evidence ZIP has not been altered.
  • The exact ZIP existed before the confirmed Bitcoin block time. It does not prove that every statement displayed on the webpage was factually correct. It also cannot guarantee how a particular court, authority or organization will evaluate the evidence.

Beaver Page Proof provides technical integrity and independently verifiable prior existence — not legal advice or an automatic guarantee of admissibility.

No Account, Subscription or Beaver Server

The architecture deliberately avoids a proprietary verification service.

There is:

  • No Beaver account
  • No subscription
  • No upload of the captured webpage
  • No developer-operated timestamp server
  • No dependence on Beaver software for later verification The final proof can be checked through the open OpenTimestamps protocol and the Bitcoin blockchain.

That independence is the central idea behind Beaver Page Proof:

Capture the page. Seal the package. Verify it anywhere.

Available on the AppStore:

https://apps.apple.com/us/app/beaver-page-proof/id6803143187

More Beaver Tools:

https://beavertools.app/

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