A Moment of Historic Reflection

  • In 1995, Netscape released a browser with HTTPS
  • For the first time, everyone had easy access to encrypted communications

20 Years Later

Security is Important

Getting a Certificate is Hard

  • Manual process, different for every provider
  • First you have to request a certificate…
  • …then you have to figure out how to install it

Why is This So Hard?

  • Certificates are required to set up a secure website
  • The entities selling them want to make money
  • This leads to things being expensive, difficult, and proprietary

is a new certificate authority

A Free CA

Things that don't matter:

  • Ability to pay
  • Where you reside
  • Individual, organization, or corporation

An Automated CA

  • Most of the work in issuing a certificate is in verifying domain control
  • Let's Encrypt uses a standard protocol to verify domain control automatically prior to certificate generation
  • Certificate renewals use this same process

Automated Certificate Management Environment (ACME)

  • Suppose someone asks for a certificate for example.com
  • How do you know they actually own example.com?

Domain Validation

Give them a challenge that only
the domain owner can complete:

  • Provision a DNS record for
  • Provision a file at
  • Configure a TLS server on example.com

Automated Validation

  • The whole process is laid out in the ACME specification
    • How you ask for authorization
    • How you fulfill challenges
    • How you ask for certificates
  • Having a standard protocol means that you can build tools
  • The vision is for ACME to be built into web servers, to auto-configure HTTPS

A Transparent CA

All certificates are publicly logged through
the Certificate Transparency system

An Open CA

Everything Let's Encrypt uses is open source:

Pull requests welcome!

A Cooperative CA

  • Wide industry sponsorship
  • Community development and support
  • Built on an open standard for all CAs

Platform Integration

An Upcoming Standard

The Future

This Line Keeps Going Upward

Only the Beginning…

  • General availability began December 3, 2015 and is already the 5th largest issuer of certificates
  • Get every website using HTTPS
  • Secure all the internet: email, chat, and more!

A Message to the World