RCS – End-to-End Encryption Specification Version 2.0

This specification defines the procedures for supporting end-to-end encryption of RCS messages and other user-provided content based on the Messaging Layer Security (MLS) protocol. It defines the overall concepts for applying MLS in the context of RCS, including the interactions between client providers, and defines the client procedures for encrypting and decrypting the RCS content. This new version improves the certificate handling and the use of encryption for file transfer next to overall improvements of the procedures.