Architecture

zkRP is built for reachability without identity: devices can find each other, relay through NATs, and receive messages while offline, without a central server that knows who is talking to whom.

Anonymous enrollment

The auth service issues blind credentials. A client proves an email is eligible and receives a credential the server cannot link back to it. The server persists only 32-byte nullifiers ("has this address enrolled?"), never an email, peer id, or issued credential. Enrollment is stateless: state that would live server-side is carried by the client in an opaque, MAC'd token. See AuthService in the API reference.

Encrypted P2P substrate

Nodes communicate over libp2p (gossipsub for pub/sub, Kademlia for discovery, circuit relay for reachability). libghost wraps this, and messages ride inside a GhostEnvelope (version, time nonce, opaque payload). Payloads are encrypted end to end; relays route without reading them.

Control plane

The controller runs a relay node and a gRPC control plane (RelayService, BlobStore, Logging, MailboxService). This is how clients discover relays, observe health and stats, move blobs, and use store-and-forward mailboxes.

Store-and-forward

Because gossipsub is ephemeral, a message for an offline recipient is stored as an opaque, end-to-end-encrypted blob under a rotating, capability-style mailbox_id and fetched on reconnect. The relay stores only mailbox id to device tokens, in memory and TTL'd, with no link to identity.