Abstract Continuous Group Key Agreement (CGKA) lets an evolving group of clients agree
on a sequence of group keys. An important application of CGKA is scalable end-to-end …

Abstract The Messaging Layer Security (MLS) protocol is an open standard for end-to-end
(E2E) secure group messaging being developed by the IETF, poised for deployment to …

Many real-world group messaging systems delegate group administration to the application
level, failing to provide formal guarantees related to group membership. Taking a …

Focusing on its cryptographic core, we provide the first formal description of the Matrix
secure group messaging protocol. Observing that no existing secure messaging model in …

Developing end-to-end encrypted instant messaging solutions for group conversations is an
ongoing challenge that has garnered significant attention from practitioners and the …

Ratcheting protocols let parties securely exchange messages in environments in which state
exposure attacks are anticipated. While, unavoidably, some promises on confidentiality and …

Abstract Continuous Group Key Agreement (CGKA) is the basis of modern Secure Group
Messaging (SGM) protocols. At a high level, a CGKA protocol enables a group of users to …

Anonymity is an (abstract) security goal that is especially important to threatened user
groups. Therefore, widely deployed communication protocols implement various measures …

Secure group messaging (SGM) protocols allow large groups of users to communicate in a
secure and asynchronous manner. In recent years, continuous group key agreements …

Continuous group key agreement (CGKA) allows a group of users to maintain a
continuously updated shared key in an asynchronous setting where parties only come …