Delta Chat on Nostr: #deltachat is secure against server-side group membership changes but for a very ...

#deltachat is secure against server-side group membership changes but for a very different reason than #signal which keeps encrypted group membership data in a central store.

Delta Chat has _no_ central store but implements a rigidly tested #p2p group membership model where servers play no role https://github.com/chatmail/models/tree/main/group-membership

Both signal and delta chat are safe against recently published attacks against #whatsapp that can add members to chats, breaking end to end encryption. https://arstechnica.com/security/2025/05/whatsapp-provides-no-cryptographic-management-for-group-messages