Mozilla rolls out new 'Encrypted Client Hello' privacy standard to all Firefox users

A few days after Cloudflare introduced the integration of Encrypted Client Hello (ECH), a new security standard, Mozilla has announced the global rollout of ECH to Firefox users. This technology aims to enhance the security and privacy of web browsing by encrypting the initial “hello” communication between a user's device and a website's server, thereby safeguarding sensitive information such as the website name from unauthorized interception.

ECH operates by utilizing a public key acquired via the Domain Name System (DNS) to encrypt the first exchange between a browser and a website. This process conceals the name of the visited site, significantly enhancing user privacy.

ECH complements other security and privacy features in Firefox, including DNS-over-HTTPS (DoH), which must be enabled in the Firefox settings for ECH to function. When used in conjunction with a virtual private network (VPN), DoH and ECH provide an additional layer of privacy and security. In this setup, the VPN conceals the user's IP address and encrypts data traffic, while ECH protects the identities of the visited websites from the VPN provider.

This new privacy technology has been under development by Mozilla for nearly five years, in collaboration with other browsers, infrastructure providers, academic researchers, and standards bodies such as the Internet Engineering Task Force (IETF). ECH is also available in Chromium 117 and is expected to see rapid adoption, at least on the client side.