MLS Group State Forks: What, Why, How

What are state forks, why can’t they happen but do anyway and how can they be resolved in OpenMLS?

Group state forks are faulty states that MLS groups can end up in. This article looks at what they are exactly, how that happens and how to resolve them. We also look at a new OpenMLS feature that …

Post-Quantum OpenMLS

Get started with post-quantum secure end-to-end encrypted with OpenMLS.

OpenMLS now offers security against harvest-now-decrypt-later (HNDL) quantum adversaries. In #1546 we merged support for the X-Wing KEM draft, which is an early draft for securely combining …

Post-Quantum Group Messaging

Get post-quantum security for end-to-end encrypted messaging with MLS.

With multiple post-quantum cryptographic algorithms (ML-KEM, ML-DSA) nearing standardization, enterprises, research groups, and standards bodies have started investigating what post-quantum secure …

Internet Defense Prize 2023

Cryspen co-founders win Usenix Security prizes

At the 32nd Usenix Security Symposium in Anaheim CA, a paper on the Messaging Layer Security Protocol, co-authored by our founders Jonathan Protzenko and Karthikeyan Bhargavan, was awarded both the …

Three (thousand) may keep a secret

An introduction to Messaging Layer Security

“Three may keep a secret, if two of them are dead.” - Benjamin Franklin (1735) However skeptical we may be of our human ability to keep secrets, we still routinely participate in group conversations …

MLS - RFC 9420

A new standard for secure messaging

✨ We are thrilled to announce the release of the MLS specification as RFC 9420. RFC 9420 is a comprehensive description of the first standardised, efficient, asynchronous, key establishment protocol …

OpenMLS

Practical Group Key Agreement for Messaging and more

Messaging Layer Security (MLS) is a security layer for end-to-end encrypting communication in large dynamic groups. It has been specified by the IETF MLS working group and designed to be efficient, …

OpenMLS

We have joined forces with our friends from Phoenix R&D to improve OpenMLS. The MLS protocol draft is in the IETF working group’s last call and is thus on track to become an RFC soon. We …