MOUNTAIN VIEW, Calif. & PHILADELPHIA--(BUSINESS WIRE)--

Today, Mozilla, the maker of Firefox, and Comcast have announced Comcast as the first Internet Service Provider (ISP) to provide Firefox users with private and secure encrypted Domain Name System (DNS) services through Mozilla's Trusted Recursive Resolver (TRR) Program. Comcast has taken major steps to protect customer privacy as it works to evolve DNS resolution.

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“Comcast has moved quickly to adopt DNS encryption technology and we’re excited to have them join the TRR program,” said Eric Rescorla, Firefox CTO. “Bringing ISPs into the TRR program helps us protect user privacy online without disrupting existing user experiences. We hope this sets a precedent for further cooperation between browsers and ISPs.”

For more than 35 years, DNS has served as a key mechanism for accessing sites and services on the Internet. Functioning as the Internet’s address book, DNS translates website names, like firefox.com and xfinity.com, into the Internet addresses that a computer understands so that the browser can load the correct website.

Over the last few years, Mozilla, Comcast, and other industry stakeholders have been working to develop, standardize, and deploy a technology called DNS over HTTPS (DoH). DoH helps to protect browsing activity from interception, manipulation, and collection in the middle of the network by encrypting the DNS data.

Encrypting DNS data with DoH is the first step. A necessary second step is to require that the companies handling this data have appropriate rules in place – like the ones outlined in Mozilla's TRR Program. This program aims to standardize requirements in three areas: limiting data collection and retention from the resolver, ensuring transparency for any data retention that does occur, and limiting any potential use of the resolver to block access or modify content. By combining the technology, DoH, with strict operational requirements for those implementing it, participants take an important step toward improving user privacy.

Comcast launched public beta testing of DoH in October 2019. Since then, the company has continued to improve the service and has collaborated with others in the industry via the (), the (EDDI), and other industry organizations around the world. This collaboration also helps to ensure that users’ security and parental control functions that depend on DNS are not disrupted in the upgrade to encryption whenever possible. Also in October, Comcast , including reaffirming its longstanding commitment not to track the websites that customers visit or the apps they use through their broadband connections. Comcast also introduced a new to help customers manage and control their privacy settings and learn about its privacy policy in detail.

“We’re proud to be the first ISP to join with Mozilla to support this important evolution of DNS privacy. Engaging with the global technology community gives us better tools to protect our customers, and partnerships like this advance our mission to make our customers’ internet experience more private and secure,” said Jason Livingood, Vice President, Technology Policy and Standards at Comcast Cable.

Comcast is the latest resolver, and the first ISP, to join Firefox’s TRR Program, joining Cloudflare and NextDNS. Mozilla began the rollout of encrypted (DoH) by default for US-based Firefox users in February 2020, but began testing the protocol in 2018.

Adding ISPs in the TRR Program paves the way for providing customers with the security of trusted DNS resolution, while also offering the benefits of a resolver provided by their ISP such as parental control services and better optimized, localized results. Mozilla and Comcast will be jointly running tests to inform how Firefox can assign the best available TRR to each user.

About Mozilla

Mozilla is the not-for-profit behind the popular web browser, Firefox. We believe the Internet is a global public resource, open and accessible to all. We work to ensure it stays open by building products, services and programs that put people in control of their online lives, and contribute to a healthier Internet. Firefox protects people’s privacy and empowers users to make smart choices in their online life. Visit for more information. To download Firefox for yourself visit .

About Comcast

Comcast Corporation (Nasdaq: CMCSA) is a global media and technology company with three primary businesses: Comcast Cable, NBCUniversal, and Sky. Comcast Cable is one of the United States’ largest high-speed internet, video, and phone providers to residential customers under the Xfinity brand, and also provides these services to businesses. It also provides wireless and security and automation services to residential customers under the Xfinity brand. NBCUniversal is global and operates news, entertainment and sports cable networks, the NBC and Telemundo broadcast networks, television production operations, television station groups, Universal Pictures, and Universal Parks and Resorts. Sky is one of Europe's leading media and entertainment companies, connecting customers to a broad range of video content through its pay television services. It also provides communications services, including residential high-speed internet, phone, and wireless services. Sky operates the Sky News broadcast network and sports and entertainment networks, produces original content, and has exclusive content rights. Visit for more information.

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