Browse past issues of ISRG's newsletter, including updates from Let's Encrypt, Prossimo, and Divvi Up. You can sign up to receive these emails at the bottom of this page.
Brighter Bytes - March 2026 Newsletter
Six-Day and IP Address Certificates Available in Certbot • Say Hello at RSAC! • ISRG Named One of Six Awardees in Common Good Cyber Fund Pilot • Zero Knowledge Proofs
Read moreBrighter Bytes - February 2026 Newsletter
DNS-PERSIST-01: A New Model for DNS-based Challenge Validation • Renewed Funding from Craig Newmark Philanthropies • On the Importance of "Hello" and "Thanks"
Read moreBrighter Bytes - January 2026 Newsletter
6-day Certs For All! • Prossimo Updates • Sponsor Shout-Out • Say Hello! • Happy New Year! • ICYMI: A Note from our Executive Director
Read moreBrighter Bytes - December 2025 Newsletter
Decreasing Certificate Lifetimes to 45 Days • New "Generation Y" Hierarchy of Root and Intermediate Certificates • Let's Encrypt CT Log Update • 10 Years of Let's Encrypt Certificates • Zero Knowledge Proofs from Credentials • Sponsor Shout-Out • Say Hello at FOSDEM!
Read moreUpcoming Changes to Let’s Encrypt Certificates
Read moreHappy Giving Tuesday! Plus… our 2025 Annual Report
Read moreBrighter Bytes - November 2025 Newsletter
Read moreBrighter Bytes - October 2025 Newsletter
Let’s Encrypt Updates • ACME Renewal Information (ARI) Published as RFC 9773 • Native ACME Support Comes to NGINX • OCSP Service Reaches End of Life • RFC 6962 Certificate Transparency Logs EOL • Prossimo Updates • Improving Error Handling in Rustls for Better Usability • Rustls Joins the Rust Foundation’s Rust Innovation Lab • New Sponsor and Donor Announcement • Say Hello at ATO! • We are Hiring! • Director of Advancement (Corporate Sponsorships) • Assistant Director of Advancement (Grants)
Read moreWe issued our first cert 10 years ago!
Ten Years Since our First Certificate!
Read moreOCSP Service Has Reached End of Life
Read moreSwitching issuance to new intermediates
Read moreBrighter Bytes - August 2025 Newsletter
A Reminder: Ending OSCP Support August 6, 2025 • Prossimo Updates • sudo-rs Headed to Ubuntu • Opportunistic Encryption Is Coming to Hickory DNS • Welcome New Sponsors
Read moreBrighter Bytes - July 2025 Newsletter
We've Issued Our First IP Address Certificate • Expiration Notification Service Has Ended • Reflections on a Year of Sunlight • Prossimo Updates • Compatibility with C is Key for Memory Safe Software • Divvi Up Updates • ICYMI: Detecting Privacy Harms in Digital Identity using Divvi Up
Read moreYour Email Address and Let’s Encrypt
Your email address and Let's Encrypt
Read moreBrighter Bytes - May 2025 Newsletter
Ending TLS Client Authentication Certificate Support in 2026 • How Pebble Supports ACME Client Developers • Prossimo Updates • $20,000 rav1d AV1 Decoder Performance Bounty • Rustls Server-Side Performance • Divvi Up Updates • Detecting Privacy Harms in Digital Identity using Divvi Up • Ten Years of Let's Encrypt • Sustaining a More Secure Internet: The Power of Recurring Donations • Welcome New Sponsors
Read moreEnding TLS Client Authentication Certificate Support in 2026
Read moreBrighter Bytes - April 2025 Newsletter
Researching the Human Digital Identity Space • Now Serving 600,000,000 Active Domains • Tenth Anniversary Sponsorships Available • New Sponsorship Tier Celebrates Ten Years of Let's Encrypt. • Recurring Donations make our work possible • Building a community of supporters
Read moreRemoving OCSP URLs from Certificates
Read moreBrighter Bytes - March 2025 Newsletter
Ten Years of Let's Encrypt: Announcing support from Jeff Atwood • A refreshed Let's Encrypt Website • Out and about • Reminder: how to stay engaged with us • New ISRG email newsletters now available. • Stay on top of cert expiration, if you need it. • A community here for you. • Recurring Donations make our work possible • Building a community of supporters
Read moreProssimo Update: Risk & Opportunity | Linux Kernel Update
How Prossimo's Risk and Opportunity Criteria Help Us Plan • An Update on Memory Safety in the Linux Kernel
Read moreAdding CRL URLs in Certificates
Read moreProssimo Update: HickoryDNS moving towards production readiness
Hickory DNS is Moving Toward Production Readiness
Read moreBrighter Bytes - February 2025 Newsletter
We Issued Our First Six Day Cert • Our FOSDEM Recap • New ISRG email newsletters now available. • Stay on top of cert expiration, if you need it. • A community here for you. • Encryption for Everybody • Join our global community of sponsors!
Read moreSupport for OCSP Must-Staple Now Disabled
Read moreBrighter Bytes - January 2025 Newsletter
Ten Years of Let's Encrypt! • Optional Short-Lived Certificates Coming Soon • Introducing Profile Selection for Certificates • FOSDEM, here we come! • Memory Safety Highlighted by the Global Cyber Alliance • Plan to End Certificate Expiration Notification Emails
Read moreBrighter Bytes - December 2024 Newsletter
ISRG's 2024 annual report • Growing momentum for Rustls adoption • Ending OCSP services in 2025 • Welcome New Sponsors! • Consider a Let's Encrypt Sponsorship in 2025
Read moreOur 2024 Annual Report Is Here
Read moreBrighter Bytes - November 2024 Newsletter: Special Edition
"As a nonprofit, 100% of our funding comes from charitable contributions." • Welcome New Sponsors • We're thrilled to welcome three new Sponsors this month! • Add Let's Encrypt Sponsorship to your 2025 budget
Read moreBrighter Bytes - October 2024 Newsletter
Rustls Outperforms OpenSSL and BoringSSL • Secure Our World • Partnering with Princeton to improve Internet security • Divvi Up at All Things Open • Welcome new Silver Sponsor! • Add Let's Encrypt Sponsorship to your 2025 budget
Read moreBrighter Bytes - September 2024 Newsletter
Let's Encrypt Growth • Eliminating Memory Safety Vulnerabilities at the Source • Big Steps Forward for River • Bringing Memory Safety to AV1 Video Decoding • Take9 • Add a Let's Encrypt Sponsorship to your 2025 budget!
Read moreBrighter Bytes - August 2024 Newsletter
Encryption for Everybody • TRanslating All C TO Rust • Privacy preserving telemetry with Divvi Up - a command line introduction • Combining privacy preserving telemetry with differential privacy • Nonprofits helping nonprofits • Welcome to our newest Silver Sponsor!
Read moreSupport Let's Encrypt. Help provide encryption for everybody.
Read moreBrighter Bytes - July 2024 Newsletter
Halfway through 2024 • Memory Safety Impacts Everybody • Prossimo is on LinkedIn! • Intent to End OCSP Service • Welcome to our newest Silver Sponsor!
Read moreISRG Brighter Bytes June 2024 Newsletter
Memory Safe NTP for Let’s Encrypt: Deploying ntpd-rs • Representing Prossimo at AWS re:Inforce • Encrypted Client Hello (ECH) Support for Rustls • Prossimo is now on LinkedIn! • Increasing domain validation security from BGP attacks
Read moreISRG Brighter Bytes May 2024 Newsletter
REMINDER: Let's Encrypt switching to new intermediates June 6 • Takeaways from Tailscale's adoption of ARI • Kristin Berdan joins ISRG as General Counsel • Rustls gains OpenSSL and Nginx compatibility • Fedora Linux RPM packages for ntpd-rs and sudo-rs • Privacy, enforced by technology
Read moreISRG Brighter Bytes April 2024 Newsletter
No more rate limits for certificate renewals with ARI • Readout from Tectonics • Deploying New Issuance Chains for Let’s Encrypt • PQ Key Exchange Support in the Rustls TLS Library
Read moreSupport our Brighter Days campaign
Read moreISRG Brighter Bytes March 2024 Newsletter
Introducing Sunlight! • ☀️ Help us build a brighter Internet! ☀️ • River Reverse Proxy • Reducing Dependencies in sudo-rs • New Intermediate Certificates • Rustls TLS library using AWS Libcrypto, now has FIPS support • 2024: The Year of Memory Safety
Read moreIntroducing our new CT log, Sunlight
Read moreISRG Brighter Bytes February 2024 Newsletter
I went to FOSDEM and all I got was this free cert… well, actually there was so much more! • Our 2023 Annual Report • Automating releases for bindgen • The first step in shortening the Let’s Encrypt chain of trust • Data Privacy Week Recap • Writing standards for the Distributed Aggregation Protocol at the IETF • We are thrilled to announce a new Silver sponsor!
Read moreISRG Brighter Bytes January 2024 Newsletter
Public benefit Internet infrastructure is not a “one-and-done” project • Small but Mighty • Securing the Web: Rustls on track to outperform OpenSSL • Data Privacy Week: January 21 - 27 • We are thrilled to announce a new Silver sponsor!
Read moreISRG Brighter Bytes December 2023 Newsletter
2023 in Review • Issuing a Challenge • Shifting the Memory Safety Paradigm • Helping Fellow Helpers • We are delighted to introduce a new Silver sponsor! • 2024 Sponsorships
Read moreSupport Let’s Encrypt today for Giving Tuesday!
Read moreISRG Brighter Bytes November 2023 Newsletter
Celebrating a decade of helping build a more secure Internet • The Beginning of Let's Encrypt • Tectonics 2023: A Productive Convening to Accelerate Memory Safety • IETF 118 • Simplifying Issuance for Very Long Domain Names • We are thrilled to introduce a new Silver sponsor! • Consider a Sponsorship
Read moreHelp Us Spread Cybersecurity Awareness
Read moreISRG Brighter Bytes October 2023 Newsletter
Securing Our World • Global Encryption Day • (Re)Introducing Hickory DNS • Secure by Design • Bringing Privacy-Respecting Telemetry to Human Rights Defenders • Divvi Up and Firefox • Ten Years of Building a Brighter Web • Learning from Let's Encrypt's Ten Years of Success • Consider a Sponsorship!
Read moreISRG Brighter Bytes September 2023 Newsletter
The Big Byte: Let's Encrypt turns eight • Increase your security governance with CAA • OpenSSF provides $530k for Rustls and Rust for Linux • The first stable release of a memory safe sudo implementation • Join us for Tectonics • How HTTPS Works • Hoodie for your thoughts? • Ten Years of building a brighter Web • Thanks to our community of donors around the world
Read moreLet's Encrypt issued its first cert 8 years ago today.
Read moreHelp us build a brighter web year round
Just like back to school, our fundraising campaign is in full swing.
Read moreBrighter Bytes - August 2023 Newsletter
The Big Byte: All sorts of security and privacy news • Let’s Encrypt issues 35 certs every second • CISA’s Cybersecurity Strategic Plan • Sovereign Tech Fund invests in Pendulum • Confluent and Let’s Encrypt • Omidyar Network funds Divvi Up • Now Open: The Divvi Up waitlist • Ten Years of building a brighter Web • From EFF: Celebrating Ten Years of Encrypting the Web
Read moreBrighter Bytes - July 2023 Newsletter
The Big Byte: Shortening the Let's Encrypt Chain of Trust • $1.5M from Sovereign Tech Fund to Fuel Memory Safety • National Cybersecurity Strategy Implementation Plan • Chainguard: Advancing memory safe programming • From The Register: Out-of-bounds, out of control • ACME is Uptime • IETF 117 • From Berkeley: A hub for real-world MPC deployments • Ten Years of building a brighter Web • 2023 is ISRG's 10th Anniversary • People Spotlight: Meet Ameer • Join our team • Supporting our nonprofit mission
Read moreJune ISRG Newsletter
The Big Bytes: The Anniversary of our 100 Millionth Cert • More Bright Bytes People Spotlight: New Staff Round-Up • News from our Parent Organization, ISRG! Learn about the 10th Anniversary of ISRG from our Executive Director • Updates from Our Sibling Projects News from sudo and su • Event Round-Up: Smallstep at OSN and ISRG visits the Cyber Civil Defense Summit ISRG Joins Smallstep at OSN
Read moreISRG Celebrates 10 Year Anniversary
10 Years of Building a Better Internet • A Timeline of ISRG’s Accomplishments
Read moreMay Brighter Bytes from Let's Encrypt and ISRG
The Big Bytes: Let's Encrypt and the Certificate Ecosystem • News from our Parent Organization, ISRG! • Updates from our Sibling Projects • Event Round-Up: Visit us at Open Source North! • New Sponsors!
Read moreApril Brighter Bytes from Let’s Encrypt and ISRG
The Big Bytes: Let's Encrypt Issues Three Million Certificates Daily • Updates from our Sibling Projects • Divvi Up and Distributed Aggregation Protocol (DAP) Developments • Major Initiative Updates From Prossimo • Event Round-Up: IETF, OSS, and Tweede golf, Oh My! • Be Part of ISRG's 10th Anniversary
Read moreMarch Brighter Bytes from Let's Encrypt and ISRG
The Big Bytes: CAA and ARI • More Bright Bytes • A Look at our Engineering Culture • Thanking our 2023 Renewing Sponsors • News from our Parent Organization, ISRG! • ISRG is now a Member of the Linux Foundation • Craig Newmark Funding • Updates from Our Sibling Projects • A Big Quarter for Prossimo and Memory Safety • New Sponsors!
Read more