May 2014 Summaries

The CloudFlare team is preparing for HostingCon 2014, taking place in Miami Beach. This will be their fourth year at the event and they are excited to meet with partners, customers, and friends. They offer complimentary limousine transfers from Miami International Airport to Loews Miami Beach Hotel on June 15th for those who reserve a spot. Attendees can also look forward to CloudFlare t-shirts, live music during breakfast each morning, and the opportunity to try their signature Nerf Railguns (limited quantity available). As a newcomer to HostingCon, Ashley Gorringe encourages visitors to stop by Booth #407 to learn about CloudFlare's new features and products. The event will feature various activities, including breakfast sponsored by CloudFlare on June 16th and 17th, a welcome reception, and happy hour at their booth.

CloudFlare hosts educational Meetups that bring together industry leaders and experts to discuss topics such as programming languages, databases, and cryptography. Their latest series on cryptography covers a wide range of topics including elliptic curves, secure messaging, password-authenticated encryption, lattice-based cryptography, new blockchain modes, fully homomorphic cryptography, and memory-hard hashing algorithms. The next crypto Meetup is scheduled for July 16th, with presenters still being sought after. Previous speakers have included Brian Warner from Mozilla discussing the security of Firefox ecosystem, Michael Hamburg from Cryptography Research presenting on elliptic curves, and independent cryptographic consultant Trevor Perrin sharing his thoughts on designing next-generation protocols for secure communication applications.

The text discusses the history and functionality of the tcpdump tool and its kernel counterpart, the packet filter interface. It explains how tcpdump works by parsing a readable filter expression into a short program in BPF bytecode, which is then attached to the network tap interface for filtering packets. The article also highlights the use of BPF filters in various applications such as traffic shaping, syscalls filtering, and iptables module. It concludes by emphasizing the continued usefulness and speed of BPF, even without enabling its just-in-time compiler.

In May 2014, John Graham-Cumming discussed the reasons behind Cloudflare's decision to continue supporting the RC4 encryption method despite its vulnerability to attacks. The company had debated whether to turn off RC4 altogether but decided against it due to a small percentage of web browsers still needing it. An analysis revealed that 0.000002% of requests to Cloudflare used the RC4 protocol, with users falling into four main categories: those passing through proxies, older phones, other miscellaneous cases, and software checking for updates or using old email programs and ancient operating systems. The company would like to stop supporting RC4 altogether but continues to offer it for a small number of clients who cannot connect more securely.

Cloudflare has decided to remove support for RC4 as a preferred cipher, instead favoring AES-based cipher suites for all HTTPS connections due to the threat landscape changes and best practices in cryptographic primitives. The decision was made after considering that most major browsers now support TLS 1.2 standard where AES-CBC is not vulnerable to BEAST attacks, and evidence of mounting weaknesses in RC4 cipher. By choosing AES-CBC, Cloudflare aims to provide long-term forward secrecy for its customers' data.

John Graham-Cumming has created a Github repository called "sslconfig" to document changes in SSL configuration for serving HTTPS as the security landscape evolves. The repository includes historical updates from an internal source and will be synchronized with current configurations. Changes have been made due to attacks on SSL/TLS, such as Lucky 13, BEAST, and biases in RC4. OpenSSL has been modified to prevent the use of RC4 for TLS 1.1 and above, introducing ECDSA, and examining suitable ciphers for maximum security. The author encourages feedback and contributions through comments, criticisms, and pull requests.