Glossary

Account — an Ethereum keypair generated locally by Pombo. Your address is your identity; no registration exists anywhere.

Admin stream — the third stream of every channel, writable only by the owner, carrying moderation state (bans, hidden messages, pins).

Channel — Pombo's group space: a set of three Streamr streams (messages, ephemeral, admin) owned by its creator.

DM inbox — your personal mailbox stream, derived from your address and created on-chain (a one-time small fee). Anyone can deposit (publish); only you can read (subscribe). It publishes your encryption public key so others can seal messages to you, and carries your encrypted cross-device sync data.

Ephemeral publisher key — the throwaway keypair Pombo uses as your network-level identity in a channel session, so your real account never appears on the wire. Discarded when you leave.

Ephemeral stream — a channel's unstored stream: presence, typing indicators and live media transfer. Nothing published here is archived.

Guest mode — a throwaway account with no persistence, for looking around. Guests have no DM inbox, so no DMs and no sync.

k-anonymity tag — the 1-byte destination hint in push wake signals. With only 256 buckets, many users share each tag, so the relay can't tell who a notification is for.

Mesh sharing — live P2P file transfer between online peers over the ephemeral stream. Needs an online seeder.

Native channel (on-chain channel) — a channel whose membership is enforced by per-address permissions recorded on Polygon. The only channel type with enforceable bans.

Password channel — a channel encrypted client-side with a key derived from a shared password (PBKDF2 → AES-256-GCM). The network sees only ciphertext.

Persistent sharing — storage-node-backed file transfer: files are chunked into the channel's stored stream, downloadable for the retention period with the sender offline.

POL — Polygon PoS's native currency, used for the small network fees on on-chain actions (creating channels, your DM inbox, managing native-channel members, changing retention or storage nodes).

Publisher proof — a signature by your real account over your ephemeral publisher key, letting other Pombo clients verify who you are. Public in public channels; sealed inside the encryption envelope in password channels and DMs.

Relay (push relay) — a community-runnable server that converts Streamr wake signals into Web Push notifications, blind to content and identities.

Retention — how long a storage node keeps a stream's history; chosen by the channel owner, 180 days by default.

Sealed sender — Pombo's DM envelope: the sender's identity travels inside the ciphertext, so even the recipient's inbox doesn't reveal who wrote until the recipient decrypts.

Storage node — a Streamr node (typically backed by Cassandra) that archives stream history and serves it back, enabling offline delivery and history.

Stream — Streamr's pub/sub primitive: a named, on-chain-registered topic that peers publish to and subscribe from. Everything in Pombo is built from streams.

Streamr Network — the decentralized P2P pub/sub network Pombo uses as its message transport.

Wake signal — a contentless push trigger broadcast when someone messages you: just a k-anonymity tag plus proof-of-work. Your device wakes and fetches the real message from the network.