Utopia Tech
Engineering5 min read

Building a certificate authority for the whole Internet

Twelve years ago, during Birthday Week 2014, we turned on Universal SSL and nearly doubled the number of encrypted sites on the web overnight, giving free TLS to every site behind Cloudflare, including the ones that never paid us a cent. Encryption stopped being an expensive, time-intensive undertaking and instead became the default. For Birthday Week this year, we are taking t

UT

Utopia Tech

September 29, 2026 · 5 min read

Share

Twelve years ago, during Birthday Week 2014, we turned on Universal SSL and nearly doubled the number of encrypted sites on the web overnight, giving free TLS to every site behind Cloudflare, including the ones that never paid us a cent. Encryption stopped being an expensive, time-intensive undertaking and instead became the default. For Birthday Week this year, we are taking the next step on that path.

For more than a decade we have been one of the largest consumers of publicly trusted certificates on the Internet, and have never issued a single one ourselves. That is changing. Cloudflare is announcing our intent to become a public certificate authority (CA).

Today we are announcing the first concrete milestones in that effort: We have applied for inclusion in the Chrome, Apple, Microsoft, and Mozilla root programs, and we have signed a definitive agreement to acquire an established, broadly trusted root from GlobalSign, so that we can offer certificates with the widest possible device reach the day we begin issuing.

We’re also announcing our plans to be one of the first CAs to serve post-quantum certificates, targeting Chrome’s recently announced Quantum-resistant Root Program . We are not issuing certificates yet, and it will be a little while before we do. What we are doing is committing to the work in public, sharing the milestones as they land, and telling you exactly what we are building while working with the root programs and other members of the WebPKI community to achieve this.

Two paths to trust A brand-new root is not widely useful for years. Even after a root program accepts it, that root has to propagate out into the world's operating systems, browsers, and devices, and it never reaches the large set of devices that have stopped receiving updates, or never received them in the first place. That long tail of older clients is where a great deal of the world’s Internet traffic originates, and where a correspondingly large set of avoidable breakage lives.

We believe that all clients deserve the highest level of security possible, regardless of their manufacturer, operating system, or time since last update. Acquiring an existing root with a high degree of trust store coverage across a diverse set of clients solves that on day one. The existing GlobalSign root has been trusted across browsers, operating systems, and devices since 2012, and it reaches older clients that a fresh root never will.

The new root that we will be submitting for inclusion in root key programs is built for where the ecosystem is heading, including the programs that are starting to cap how old a trusted root may be. The established root gives us reach across the devices of the past. The new roots give us standing under the policies of the future.

We want both to ensure certificates issued by our CA provide the widest set of customer compatibility possible. A new source of free certificates The free-of-charge, automated certificate model now carries most of the encrypted web, and much of it runs through one remarkable operator. Let's Encrypt issues on the order of ten million certificates a day, serves more than 500 million sites, and passed four billion active certificates in 2025.

It is one of the best things to happen to the Internet in twenty years, and we say that as one of its largest users. That success comes with some systemic risk: if the dominant free certificate authority had a bad week, much of the web would have no comparable free, automated alternative ready to take the load. At the certificate pack level, we have spent years building exactly this kind of redundancy for our own customers.

Every Cloudflare Universal SSL certificate already ships with a backup certificate, wrapped with a separate key and issued from a different authority, ready to deploy automatically if the primary is ever revoked or compromised. A public CA is that same idea, but at the scale of the whole Internet. To make it easy to adopt, we will be Automated Certificate Management Environment ( ACME )-first, an open standard protocol that is widely accepted.

Automated issuance and renewal through ACME will be the way you get a certificate from us, which means anyone already pointed at any existing free CA can move to us by changing a directory URL, with no new tooling and nothing to re-architect. Certificate growth projections are huge Cloudflare sits in front of more than 20 percent of global Internet request traffic and terminates TLS for millions of domains, relying on millions of certificates per year to do so.

We provision those certificates through multiple CAs, with primary and backup paths so customer services stay up through CA outages and revocation events. That has taught us not just how the WebPKI ecosystem works, but also that it occasionally fails, from the consuming side, the hard way. We have dealt with rate limits, validation edge cases, revocation latency, chain building, and root distribution lag.

We have lived through the CA churn of recent years and felt it through our customers. We know what reliable issuance has to look like from the outside, because our customers' uptime has depended on us being resilient and responsive when an issuer has a bad day. And as certificate maximum validity period decreases over the next few years, agentic activity increases, and PQ certs go mainstream, we expect the raw number of certificates we rely on annually on to continue to grow, quickly — and we are not alone.

We want to not just solve this problem for ourselves, but be part of providing this utility to the Internet, and ensure that the certificate supply chain for our customers has even more providers. Designing for resilience: transparency and fail small In taking on this new responsibility of being our own CA, we're committed to making the most reliable and resilient CA possible.

Originally published at blog.cloudflare.com

Share
▸ Want a deeper look?

Talk to an architect about applying this to your stack.

60-minute technical evaluation, no obligation. We'll map the ideas in this article to your environment.

Skip to main content