Internet Security Research Group

Organization
Type	Non-profit
Focus	Internet security; Web PKI
Region	NA
Country	United States of America
City	San Francisco, California
Founded	2013/05/24
Founders	Josh Aas Eric Rescorla J. Alex Halderman Peter Eckersley
Websites	abetterinternet.org isrg.org

Internet Security Research Group (ISRG) is a U.S.-based tax-exempt public-benefit nonprofit focused on improving Internet security and privacy by operating public-interest security infrastructure projects. It is best known for operating Let's Encrypt, a publicly trusted Certificate Authority that issues free, automated [[TLS certificates at global scale.

History

ISRG was founded in May 2013 as a nonprofit home for public-benefit digital infrastructure projects. ISRG’s founding directors were Josh Aas and Eric Rescorla, and early institutional support for the effort came from organizations including Mozilla, the Electronic Frontier Foundation (EFF), the University of Michigan, Cisco, and Akamai.

Projects

Let's Encrypt

Let's Encrypt is ISRG’s best-known project and a major driver of mainstream deployment of HTTPS on the public web. Let’s Encrypt was designed to remove cost and operational friction from certificate issuance by combining free certificates with high automation. In ISRG’s reporting, Let’s Encrypt has operated at a scale measured in hundreds of millions of websites, issuing large volumes of certificates daily.

A core enabling component of this model is the ACME Protocol (Automatic Certificate Management Environment), standardized at the IETF as RFC 8555. ACME allows certificate requests, domain control validation, issuance, and renewal to be performed programmatically, which is particularly relevant as the web PKI ecosystem trends toward shorter certificate lifetimes and more frequent automation-driven renewals.

Prossimo

Prossimo is ISRG’s initiative to reduce systemic software vulnerabilities by supporting migration of security-sensitive infrastructure to memory-safe implementations, including projects in the broader Internet services stack.

Divvi Up

Divvi Up is a privacy-preserving telemetry and metrics aggregation effort, intended to support measurement while limiting collection of identifiable user-level data.

Governance and policy relevance

ISRG’s work sits at the intersection of technical standards and operational governance for the web’s trust infrastructure. While ISRG is not part of the ICANN ecosystem, its flagship project depends on global uniqueness and stability of the Domain Name System (DNS) for certificate issuance and validation workflows, since certificates authenticate control of DNS names in the Web PKI model.

Operationally, ISRG participates in a multi-actor environment where browser root programs and the CA/Browser Forum establish baseline issuance and validation requirements, and the IETF standardizes protocols like ACME that shape how automation is implemented across the ecosystem. In practice, this combination has shifted certificate deployment from a largely manual, paid service model toward an automated, high-volume baseline expectation for public-facing services, with follow-on effects for hosting providers, registrars, CDNs, and enterprise IT operations.

ISRG publishes public documentation and open source code supporting these projects, including organizational repositories and implementation components maintained on GitHub.

See also

• IETF

X.509 Public Key Infrastructure for the Internet (RFC 5280).

North America, according to the ICANN Geographic Regions (ICANN Geographic Regions).

Allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery (RFC 8446).

Electronic Frontier Foundation

Internet Engineering Task Force

Request For Comments. Archival series dedicated to documenting Internet technical specifications, including general contributions from the Internet research and engineering community as well as standards documents (RFC Editor Model, Version 3).