Page Integrity oleh Meixler Technologies

After installing the Page Integrity extension, you’ll notice the PI button in your browser toolbar. Click the button to view integrity information about the currently loaded page in the active tab of your browser, including the SHA-256 checksum hash of the page source. Additionally, if the page source is signed with one or more digital signatures, PI will verify the signatures, and show the signer's public signing keys for these signatures. See https://www.pageintegrity.net/ for more info.