This letter was originally published in our 2022 annual report.

The past year at ISRG has been a great one and I couldn’t be more proud of our staff, community, funders, and other partners that made it happen. Let’s Encrypt continues to thrive, serving more websites around the world than ever before with excellent security and stability.

A particularly big moment was when Let’s Encrypt surpassed 300,000,000 websites served. When I was informed that we had reached that milestone, my first reaction was to be excited and happy about how many people we’ve been able to help. My second reaction, following on quickly after the first, was to take a deep breath and reflect on the magnitude of the responsibility we have here.

The way ISRG is translating that sense of responsibility to action today is probably best described as a focus on agility and resilience. We need to assume that, despite our best efforts trying to prevent issues, unexpected and unfortunate events will happen and we need to position ourselves to handle them.

Back in March of 2020 Let’s Encrypt needed to respond to a compliance incident that affected nearly three million certificates. That meant we needed to get our subscribers to renew those three million certificates in a very short period of time or the sites might have availability issues. We dealt with that incident pretty well considering the remediation options available, but it was clear that incremental improvements would not make enough of a difference for events like this in the future. We needed to introduce systems that would allow us to be significantly more agile and resilient going forward.

Since then we’ve developed a specification for automating certificate renewal signals so that our subscribers can handle revocation/renewal events as easily as they can get certificates in the first place (it just happens automatically in the background!). That specification is making its way through the IETF standards process so that the whole ecosystem can benefit, and we plan to deploy it in production at Let’s Encrypt shortly. Combined with other steps we’ve taken in order to more easily handle renewal traffic surges, Let’s Encrypt should be able to respond on a whole different level the next time we need to ask significant numbers of subscribers to renew early.

This kind of work on agility and resilience is critical if we’re going to improve security and privacy at scale on the Web.

Our Divvi Up team has made a huge amount of progress implementing a new service that will bring privacy respecting metrics to millions of people. Applications collect all kinds of metrics: some of them are sensitive, some of them aren’t, and some of them seem innocuous but could reveal private information about a person. We’re making it possible for apps to get aggregated, anonymized metrics that give insight at a population level while protecting the privacy of the people who are using those apps. Everybody wins - users get great privacy and apps get the metrics they need without handling individual user data. As we move into 2023, we’ll continue to grow our roster of beta testers and partners.

Our Prossimo project started in 2020 with a clear goal: move security sensitive software infrastructure to memory safe code. Since then, we’ve gotten a lot of code written to improve memory safety on the Internet.

We’re ending the year with Rust support being merged into the Linux kernel and the completion of a memory safe NTP client and server implementation. We’re thrilled about the potential for a more memory safe kernel, but now we need to see the development of drivers in Rust. We’re particularly excited about an NVMe driver that shows excellent initial performance metrics while coming with the benefit of never producing a memory safety bug. We are actively working to make similar progress on Rustls, a high-performance TLS library, and Trust-DNS, a fully recursive DNS resolver.

All of this is made possible by charitable contributions from people like you and organizations around the world. Since 2015, tens of thousands of people have given to our work. They’ve made a case for corporate sponsorship, given through their DAFs, or set up recurring donations. That’s all added up to $17M that we’ve used to change the Internet for nearly everyone using it. I hope you’ll join these people and support us financially if you can.