People seem to be missing that FTP and MQTT are generally insecure protocols. I think FTP is probably the bigger issue than MQTT. This kind of stuff is common in home IOT networks but would never pass security audit on a corporate network.<p>Bambu is growing up, serving more corporations beyond the hobby community, and probably has been asked to beef their security up to make it easier to deploy their printers securely.<p>Moving to Mutual TLS via a controlled client like Bambu Connect is a pretty industry standard approach to secure, authenticated communication that doesn't require an internet connection, it is done with digital signatures offline.... and thus it can be done over a LAN. It's how many web APIs inside a corporate network are secured. It's how web browsers are secured. Microsoft, Mozilla, Google, Apple, etc. all send you revised certs/keys regularly in your OS or browser patches. Client authentication via x.509 cert signature or subject verification isn't super common on the public web but it does happen a lot with mobile apps or thick client apps, or some websites, e.g. SAP's many websites often use it to verify you're a customer.