Telegram groups do not have end-to-end encryption, so you can join a group by clicking on a group link, similar to a forum.

Keychat groups are end-to-end encrypted and provide both forward and backward secrecy. It’s difficult—if not impossible—to allow users to join a group simply by clicking a group link, like in Telegram. Keychat group chats are designed for friends, and new members are invited by existing ones.

Nostr NIP-29 groups are more similar to Telegram groups.

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