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

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 …

The majority of secure messengers have single, centralized service providers that relay
ciphertexts between users to enable asynchronous communication. However, in some …

The widely used Signal protocol provides protection against state exposure attacks through
forward security (protecting past messages) and post-compromise security (for restoring …

Abstract The Digital Markets Act (DMA) is a nascent European Union regulation adopted in
May 2022. One of its most controversial provisions is a requirement that so-called …

Cryptographers rely on visualization to effectively communicate cryptographic constructions
with one another. Visual frameworks such as constructive cryptography (TOSCA 2011), the …

A secure messaging protocol, such as the Signal protocol, provides end-to-end encrypted
asynchronous communication. This paper focuses on a secure group messaging (SGM) …

Nowadays, cryptography is ubiquitous in people's daily interactions. Secure messaging
apps implement end-to-end encrypted communication channels between individuals, web …