We plan to support three types of encrypted group chats: small group, medium group, and large group. 

When a member sends a message in a small group, they are essentially sending a one-on-one message to every other group member. 

This group chat mode offers the best security, but it supports fewer group members.

This was the approach used by Signal for group chats a few years ago, and we regret that Signal has abandoned this model to accommodate more members. Signal should have retained this model and added the current sender key group mode as well.

Next week, we may release a Keychat version that supports medium groups. Compared to small groups, it will lose some backward secrecy capabilities, but it can support more group members.

Later, we will consider using the message layer security protocol to build large groups.