How GetProofAnchor (GPA) actually works

Why GPA exists

Online content changes constantly: articles get edited, posts disappear, pricing and policies move silently. A plain screenshot is easy to challenge — anyone with a graphics editor can produce something convincing in minutes, and there’s no independent way to prove when it was taken.

GetProofAnchor exists to answer one specific question with cryptographic certainty: “What was visible on this URL at that moment, and has the evidence stayed unchanged since?”

That makes online content reviewable by third parties — lawyers, regulators, investigators, journalists, compliance teams — when individuals or companies need to defend themselves against harmful, misleading, or disputed online content, or document what they themselves promised in writing.

How it works (at a glance)

1. Capture a URL — either via the dashboard (public URLs) or via the browser widget (any page you can reach in your browser, including behind login).
2. GPA generates a permanent Proof ID and stores the captured artifacts (screenshot, DOM, text, metadata).
3. The proof is anchored in a three-layer trust stack — a global hash chain, the Bitcoin blockchain, and an EU-qualified eIDAS timestamp.
4. Anyone can later verify the Proof ID online or an exported Evidence ZIP — even offline, with standard open-source tools.

Step 1 — Capture the page

GPA offers two capture paths. They produce equivalent forensic records — same Proof ID format, same Evidence ZIP — but they reach different parts of the web.

Whichever method you use, the same artifacts are recorded:

• a full-page screenshot
• the captured HTML/DOM at capture time
• extracted text content
• technical metadata — final URL after redirects, capture timestamp, content fingerprints (SHA-256 hashes)

These artifacts together represent what the page looked like, what it actually said, and how it was structured — at that exact moment.

Step 2 — Proof ID

Every capture produces a Proof ID — a permanent identifier for that record. You can share it as a link, and it will always refer to the same captured evidence, exactly as it was at creation.

Step 3 — How the trust is anchored

Tamper-evidence isn’t a single feature; it’s the result of three independent layers stacked on top of every proof. Each layer makes it harder for any party — including GetProofAnchor itself — to alter, backdate, or fabricate a record.

The result: any later change to a captured proof is detectable, and the time of capture cannot be faked — not by an attacker, not by an insider, not by GPA. Verification doesn’t depend on trusting us; it depends on math and on systems we don’t control.

Step 4 — Evidence ZIP

If you need to share or archive evidence outside your account, export an Evidence ZIP — a portable, self-contained package (format identifier: getproofanchor-evidence-1) that bundles every captured artifact together with the integrity data needed to verify it later.

Using verification you can later demonstrate that the ZIP and its contents are original and have not been modified since capture — including the screenshot, the HTML, the text, and the metadata.

Step 5 — Verification

Verification answers a single yes/no question: does this evidence still match what was originally captured? It can be performed against either form of the proof:

• a Proof ID (online verification — quick, public, no download needed)
• an Evidence ZIP (online verification or fully offline verification with standard tools)

Evidence ZIP verification is independent of GetProofAnchor. The ZIP includes the cryptographic manifest, the eIDAS timestamp response, and the OpenTimestamps Bitcoin receipt, plus a README that walks you through verification with only python3, openssl, and ots — no GPA service, no network call to our infrastructure, no account required.

Any modification to the Evidence ZIP will cause verification to fail. That includes editing extracted text, modifying a screenshot pixel, replacing files, recompressing content, or altering the ZIP structure.

Results are intentionally clear and deterministic: Match (the evidence is byte-identical to the original record) or Modified (the evidence differs from the original capture and cannot be trusted as the original).

What GPA does not do

• GPA does not assess or judge the truthfulness of captured content — only what was visible.
• GPA does not make legal decisions or replace legal counsel.
• GPA does not decide admissibility — that’s determined by authorities and jurisdiction.
• GPA does not capture retroactively — only what is visible at the moment you trigger the capture.

GPA’s role is precise and technical: it provides a verifiable, tamper-evident, time-anchored record of what was visible at a specific moment. How that record is used legally depends on context, procedure, and jurisdiction — but the technical integrity of the record itself is independently verifiable.