Are private messages end-to-end encrypted in Nostr?

Yes, private messages on Nostr are end-to-end encrypted.

The Nostr protocol uses a system of relays to transmit messages and other data between users, and it does not rely on a blockchain. Instead, it uses private and public keys for identity and message signing.

The NIP-04 protocol, which is a part of the Nostr protocol, defines the process for sending encrypted direct messages between two users[4].

Additionally, the Imp Chat mobile app, which is built on the Nostr protocol, provides end-to-end encryption for individual and group chats, ensuring that only the intended recipients can decrypt the messages[3]. Therefore, Nostr's protocol and related applications prioritize the privacy and security of user communications.

For more technical details, you can refer to the NIP-04 protocol specification on the Nostr Protocol GitHub page[5].

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