Security | Threat Detection | Cyberattacks | DevSecOps | Compliance

Anonymous credentials: rate-limiting bots and agents without compromising privacy

The way we interact with the Internet is changing. Not long ago, ordering a pizza meant visiting a website, clicking through menus, and entering your payment details. Soon, you might just ask your phone to order a pizza that matches your preferences. A program on your device or on a remote server, which we call an AI agent, would visit the website and orchestrate the necessary steps on your behalf.

Policy, privacy and post-quantum: anonymous credentials for everyone

The Internet is in the midst of one of the most complex transitions in its history: the migration to post-quantum (PQ) cryptography. Making a system safe against quantum attackers isn't just a matter of replacing elliptic curves and RSA with PQ alternatives, such as ML-KEM and ML-DSA. These algorithms have higher costs than their classical counterparts, making them unsuitable as drop-in replacements in many situations.

Defending QUIC from acknowledgement-based DDoS attacks

On April 10th, 2025 12:10 UTC, a security researcher notified Cloudflare of two vulnerabilities (CVE-2025-4820 and CVE-2025-4821) related to QUIC packet acknowledgement (ACK) handling, through our Public Bug Bounty program. These were DDoS vulnerabilities in the quiche library, and Cloudflare services that use it. quiche is Cloudflare's open-source implementation of QUIC protocol, which is the transport protocol behind HTTP/3.

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 this threat, Cloudflare is helping to migrate the Internet to Post-Quantum (PQ) cryptography.

Securing agentic commerce: helping AI Agents transact with Visa and Mastercard

The era of agentic commerce is coming, and it brings with it significant new challenges for security. That’s why Cloudflare is partnering with Visa and Mastercard to help secure automated commerce as AI agents search, compare, and purchase on behalf of consumers. Through our collaboration, Visa developed the Trusted Agent Protocol and Mastercard developed Agent Pay to help merchants distinguish legitimate, approved agents from malicious bots.

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 were vulnerable to hackers stealing crypto assets (“crypto stealing” or “wallet draining”) from end users.

Improving the trustworthiness of Javascript on the Web

The web is the most powerful application platform in existence. As long as you have the right API, you can safely run anything you want in a browser. Well… anything but cryptography. It is as true today as it was in 2011 that Javascript cryptography is Considered Harmful. The main problem is code distribution. Consider an end-to-end-encrypted messaging web application.

Introducing REACT: Why We Built an Elite Incident Response Team

Cloudforce One’s mission is to help defend the Internet. In Q2’25 alone, Cloudflare stopped an average of 190 billion cyber threats every single day. But real-world customer experiences showed us that stopping attacks at the edge isn’t always enough. We saw ransomware disrupt financial operations, data breaches cripple real estate firms, and misconfigurations cause major data losses. In each case, the real damage occurred inside networks.