I thought Mozilla was the one behind ECH. How is it enabled in Chrome, Edge, and Opera and not in Librewolf, let alone Firefox?
Is this a false negative from https://privacytests.org?
What is ECH?
IIRC, Mozilla doesn’t ship Firefox with DNS-over-HTTPS (DoH) enabled by default in most countries – and I think it only does Encrypted Client Hello (ECH) if DoH is enabled.
From LibreWolf’s website:
By default DoH is not enabled in LibreWolf.
I assume that also disables ECH by default.
What is ECH and GPC?
ECH: Encrypted Client Hello
GPC: Global Privacy Control
I don’t really understand these specs on a deep level, so I can’t summarize them for you, but these articles should be able to answer any questions you have: