Pulsar: Private Nostr Chat App That Protects Metadata

“Introducing Pulsar a private nostr chat app that protects your metadata.””Pulsar was originally prototyped by supertestnet and I joined him a few weeks ago to build out the frontend and add all of the basic features to reach an MVP.””Pulsar is still very much in early alpha phase, the code is a little messy, but it works as expected. If people like this approach I plan on rebuilding Pulsar as a native app, but for now it will live as a simple web app.””Personally my final ideal state for Pulsar would be a Signal like experience with the same privacy guarantees but without the need to provide a phone number.”

How it works

Each chat instance is encrypted with a shared secret that also acts as an invite for others to join the chat group and decrypt the messages;Each real keypair of the participants in the chat instance is wrapped in an ephemeral keypair (which is what is broadcasted to the relays);All messages are encrypted by default with the shared secret using the ephemeral keypairs;A fresh ephemeral keypair is also created for each message;All messages are padded with garbage data to give them each the same length;Additionally a padded / encrypted message is posted every 3 seconds while the instance is open (this is the pulse) which prevents outside observers from identifying the real messages AND when real messages are posted;Note that Pulsar MUST be used with Tor or alongside a VPN or you will leak your IP address.

Announcement / Archive
GitHub Repo
Clearnet Site / TOR

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