IP addresses have historically been treated as stable identifiers for non-routing purposes such as for geolocation and security operations. Many operational and security mechanisms, such as blocklists, rate-limiting, and anomaly detection, rely on the assumption that a single IP address represents a cohesive, accountable entity or even, possibly, a specific user or device. But the […]
How to build your own VPN, or: the history of WARP
Linux’s networking capabilities are a crucial part of how Cloudflare serves billions of requests in the face of DDoS attacks. The tools it provides us are invaluable and useful, and a constant stream of contributions from developers worldwide ensures it continually gets more capable and performant. When we developed WARP, our mobile-first performance and security […]
Helping protect the 2025 Moldova elections
On Sunday, September 28, 2025, the Republic of Moldova held a parliamentary election that was described as a referendum on its geopolitical future. The election was conducted amid claims of Russian interference, both online and offline. Ensuring the security of the election infrastructure was a critical priority, not just to protect the vote count, but […]
State of the post-quantum Internet in 2025
This week, the last week of October 2025, we reached a major milestone for Internet security: the majority of human-initiated traffic with Cloudflare is using post-quantum encryption mitigating the threat of harvest-now/decrypt-later. We want to use this joyous moment to give an update on the current state of the migration of the Internet to post-quantum […]
Keeping the Internet fast and secure: introducing Merkle Tree Certificates
The world is in a race to build its first quantum computer capable of solving practical problems not feasible on even the largest conventional supercomputers. While the quantum computing paradigm promises many benefits, it also threatens the security of the Internet by breaking much of the cryptography we have come to rely on. To mitigate […]
A framework for measuring Internet resilience
On July 8, 2022, a massive outage at Rogers, one of Canada’s largest telecom providers, knocked out Internet and mobile services for over 12 million users. Why did this single event have such a catastrophic impact? And more importantly, why do some networks crumble in the face of disruption while others barely stumble? The answer […]
From .com to .anything: introducing Top-Level Domain (TLD) insights on Cloudflare Radar
Readers of a certain age may remember the so-called “dot com boom” that took place in the early 2000’s. The boom’s “dot com” is what is known as a Top-Level Domain (TLD). Originally intended to organize domain names into a small set of categorical groupings, over the past 40+ years, the set of TLDs has […]
Data at Cloudflare scale: some insights on measurement for 1,111 interns
Cloudflare recently announced our goal to hire 1,111 interns in 2026 — that’s equivalent to about 25% of our full-time workforce. This means countless opportunities to develop and ship working code into production. It also creates novel opportunities to measure aspects of the Internet that are otherwise hard to observe — and more difficult still […]
Making the Internet observable: the evolution of Cloudflare Radar
The Internet is constantly changing in ways that are difficult to see. How do we measure its health, spot new threats, and track the adoption of new technologies? When we launched Cloudflare Radar in 2020, our goal was to illuminate the Internet’s patterns, helping anyone understand what was happening from a security, performance, and usage […]
How Cloudflare’s client-side security made the npm supply chain attack a non-event
In early September 2025, attackers used a phishing email to compromise one or more trusted maintainer accounts on npm. They used this to publish malicious releases of 18 widely used npm packages (for example chalk, debug, ansi-styles) that account for more than 2 billion downloads per week. Websites and applications that used these compromised packages […]
