[entropyie]

Ultimately every cert is signed by a Certificate Authority. This is a "Trust Anchor". An authority that you trust implicitly. Your web browser maintains a list of these trusted parties, which are measured in the dozens and only change occasionally after careful scrutiny by Browser vendors. If your cert is not signed by one of these CAs, there is no way to verify it's veracity. That is why the browser gives a scary warning. I could issue a cert claiming to be google.com without any deterance. Until recently all such authorities charged a fee to issue you a verified certificate. Also the process was usually not fully automated and required human intervention to renew a cert. LetsEncrypt was a major innovation for two reasons:

1. They provided the certificates for free, no strings attached 2. They provided a fully automated and optimized process to issue/renew/deploy the cert

This had the effect of making HTTPS accessible to everyone, and is the reason that HTTPS has become the default rather than only being used for a small fraction of websites (e-commerce etc...).

Overall this has been a positive development and has raised the bar against mass-surveillance across the world. However, the downside as mentioned, is that much of the world's infrastructure now relies on this small company. Since the certs are only valid for 3 months, any blockage in that renewal process means rapidly failing services.

[Tijdreiziger]

It would be interesting to see governments or domain registries set up ACME-compatible CAs.

At the moment, it looks like there are options in Norway and Austria as well as the US: https://www.xf.is/2020/06/30/list-of-free-acme-ssl-providers...

[jonas-w]

Wouldn't this allow them to easily MITM you?

[Tijdreiziger]

A lot of governments already have CAs, so they could MITM you anyway.

For example, the Netherlands government CA: https://cert.pkioverheid.nl/