26th June 2020 - Link Blog
How CDNs Generate Certificates. Thomas Ptacek (now at Fly) describes in intricate detail the challenges faced by large-scale hosting providers that want to securely issue LetsEncrypt certificates for customer domains. Lots of detail here on the different ACME challenges supported by LetsEncrypt and why the new tls-alpn-01 challenge is the right option for operating at scale.
Recent articles
- The Axios supply chain attack used individually targeted social engineering - 3rd April 2026
- Highlights from my conversation about agentic engineering on Lenny's Podcast - 2nd April 2026
- Mr. Chatterbox is a (weak) Victorian-era ethically trained model you can run on your own computer - 30th March 2026