Ask HN: Help find HN article on certifying web content

Few months back (recently) there was an article that described an algorithm to certify that - particular content was indeed fetched from a website.

Aka non-repudiation of server sent content. This is something similar to TLS-N but the author claimed it can be done on vanilla tls.

Im not able to find that article. If it rings a bell please share/help.

Thank you