Cloudflare’s mission is to help build a faster and more secure Internet. Over the last several years, the Internet Engineering Task Force (IETF) has been working on a new version of TLS, the protocol that powers the secure web. Last September, Cloudflare was the first service provider to enable people to use this new version […]
Tag Archives: tls
TLS 1.3 explained by the Cloudflare Crypto Team at 33c3
Nick Sullivan and I gave a talk about TLS 1.3 at 33c3, the latest Chaos Communication Congress. The congress, attended by more that 13,000 hackers in Hamburg, has been one of the hallmark events of the security community for more than 30 years. You can watch the recording below, or download it in multiple formats […]
TLS nonce-nse
One of the base principles of cryptography is that you can’t just encrypt multiple messages with the same key. At the very least, what will happen is that two messages that have identical plaintext will also have identical ciphertext, which is a dangerous leak. (This is similar to why you can’t encrypt blocks with ECB.) […]
An overview of TLS 1.3 and Q&A
The CloudFlare London office hosts weekly internal Tech Talks (with free lunch picked by the speaker). My recent one was an explanation of the latest version of TLS, 1.3, how it works and why it’s faster and safer. You can watch the complete talk below or just read my summarized transcript. The Q&A session is […]
Yet Another Padding Oracle in OpenSSL CBC Ciphersuites
Yesterday a new vulnerability has been announced in OpenSSL/LibreSSL. A padding oracle in CBC mode decryption, to be precise. Just like Lucky13. Actually, it’s in the code that fixes Lucky13. It was found by Juraj Somorovsky using a tool he developed called TLS-Attacker. Like in the “old days”, it has no name except CVE-2016-2107. (I […]
Introducing CloudFlare Origin CA
Free and performant encryption to the origin for CloudFlare customers In the fall of 2014 CloudFlare launched Universal SSL and doubled the number of sites on the Internet accessible via HTTPS. In just a few days we issued certificates protecting millions of our customers’ domains and became the easiest way to secure your website with […]
Beware of Unverified TLS Certificates in PHP & Python
Web developers today rely on various third-party APIs. For example, these APIs allow you to accept credit card payments, integrate a social network with your website, or clear your CDN’s cache. The HTTPS protocol is used to secure the connection with the API server. However, if your web app doesn’t verify the TLS certificate, aRead […]
Introducing CFSSL 1.2
Continuing our commitment to high quality open-source software, we’re happy to announce release 1.2 of CFSSL, our TLS/PKI Swiss Army knife. We haven’t written much about CFSSL here since we originally open sourced the project in 2014, so we thought we’d provide an update. In the last 20 months, we have added a ton of […]
Going to IETF 95? Join the TLS 1.3 hackathon
If you’re in Buenos Aires on April 2-3 and are interested in building, come join the IETF Hackathon. CloudFlare and Mozilla will be working on TLS 1.3, the first new version of TLS in eight years! At the hackathon we’ll be focusing on implementing the latest draft of TLS 1.3 and testing interoperability between existing […]
TLS Certificate Optimization: The Technical Details behind “No Browser Left Behind”
Overview Back in early December we announced our “no browser left behind” initiative to the world. Since then, we have served well over 500 billion SHA-1 certificates to visitors that otherwise would not have been able to communicate securely with our customers’ sites using HTTPS. All the while, we’ve continued to present newer SHA-2 certificates […]
