Understand what leaves your device.

We tested the same Alpha 3 package offered for download. In a fresh Chromium profile, with the browser offline and synthetic ChatGPT/Claude pages, local name detection, masking, restoration and pause/settings worked. Only two document requests were observed; both were fulfilled locally by the test. No unexpected HTTP(S) requests or page WebSocket attempts were observed in these workflows. A separate control confirmed that the recorder detected a deliberate network attempt.

The ZIP’s manifest.json declares offscreen (local scanner) and sidePanel (settings). Content scripts match chatgpt.com and claude.ai only. No host_permissions or externally_connectable are declared. Extension pages use connect-src 'self', allowing their own packaged resources. This is not a blanket network ban on content scripts, and none of these settings alone proves data leakage impossible.

Extension network requests · Chrome documentation ↗
Content-script security policy · Chrome documentation ↗

1. Download the Alpha 3 ZIP and compare its SHA-256 with the value below. Extract it into a fresh folder without changes.
2. Download the verification script. In an empty folder with Node 22 or later, install Playwright and Chromium using the commands below. Tool installation needs internet; the workflow test then runs offline.
3. Run the script with paths to the ZIP and its extracted extension subfolder. It checks release identity, uses a temporary browser profile and writes report.json. Inspect the script yourself; it uses fabricated text only.

npm install playwright@1.63.0
npx playwright install chromium
node verify-local-processing.mjs /path/to/dmz-chromium-extension-0.1.3-alpha.3.zip /path/to/extension report.json

SHA-256 identifies the file; it does not establish its safety:6e59e15141a251bee8fb0300acb2ff681bba0d213d744ee264e7a94a4ba66c91

This is a bounded maintainer test, not an independent audit or proof that networking is technically impossible. It does not include OS packet capture, a DNS/QUIC audit or all browser background traffic. It uses mocked pages, not authenticated AI services. It applies only to this release and must be repeated for a new package.

ChatGPT and Claude can see the original composer draft and handle their own network traffic. Paused masking, detection misses and unchanged attachments can expose information through the AI site. Links you open from settings visit DMZ/Kastro websites. dmz.is itself requires network access; this is not a claim that your browser or AI website is offline.

You can also inspect Network in DevTools for the service worker and extension pages from chrome://extensions, plus the content script in the chat tab. Start recording before testing and use fabricated data only. One empty Network panel does not cover all browser processes. An independent audit would add assurance; none has been completed.