Privacy Policy

Unblock is designed to work without an account, without a server, and without collecting personal data. We do not run analytics, we do not attach an advertising ID, and we do not upload your contacts, location, or messages to any service under our control.

None on our servers. Unblock has no backend operated by us. All data the app processes is stored on your device in an encrypted local database: • Device identity (Ed25519 keypair) — for signing your broadcasts — encrypted at rest (PIN-derived key, Argon2id) • Channel keys (content encryption keys) — for decrypting messages from channels you follow — encrypted at rest (database encryption) • Channel metadata (name, size/rate limits) — for enforcing channel rules locally — not encrypted • Messages (ciphertext + signatures) — for displaying channel content — encrypted at rest (XChaCha20-Poly1305) • Following list (channel public keys) — for knowing which channels to relay and display — not encrypted • Outbox (unsent messages) — store-and-forward when the mesh is unavailable — encrypted at rest (same as messages) Not stored: phone number, email, IP address, location, contacts, browsing history, device identifiers, or any other personally identifiable information (PII).

When you broadcast a message, Unblock relays it over: • Bluetooth Low Energy (BLE) mesh — to nearby devices in radio range. • Wi-Fi Direct / Aware — to nearby devices for higher throughput. • LoRa (sub-GHz radio) — for long-range, low-bandwidth relay when paired with a LoRa-capable accessory. • Nostr relays over the internet (optional) — if you have configured relay URLs and internet is available. Mesh frames are wrapped in Nostr events (kind 30078) and sent via WebSocket. The relay receives the encrypted frame and the bridge's ephemeral public key — nothing else. The relay cannot read message content (it is encrypted under the channel key, which is never sent to the relay). The relay does see the connecting device's IP address, as with any WebSocket connection — use Tor or a VPN if this is a concern. No IP addresses, device identifiers, or location data are included in mesh frames. Public channel messages are signed but not encrypted so any recipient can verify the sender. Nostr relays are third-party servers you choose to connect to. Each relay operator has its own policy. We do not operate any relay.

• Bluetooth Scan / Connect / Advertise — Discover and relay to nearby devices over BLE mesh • Nearby Wi-Fi Devices — Form Wi-Fi Direct peer groups • Access Fine Location — Required by Android for BLE scanning — we do not record or transmit location • Camera — Scan channel QR codes for joining • Post Notifications, Foreground Service, Wake Lock — Keep the mesh service running while the screen is off • Internet — Optional Nostr relay bridge We do not request contacts, phone, SMS, microphone, or files.

Unblock is not directed to children under 13. We do not knowingly collect information from anyone.

All data lives on your device. Uninstalling the app deletes it. You can also wipe the local database from Settings inside the app. Panic wipe: The Settings screen includes a panic-wipe button that immediately and irreversibly deletes the entire storage directory — your identity keypair, all channels, all messages, the following list, and the outbox — then restarts the app as if freshly installed. This is designed for situations where you need to destroy all evidence of use.

• Nostr relays you configure. Their operators may log connections, IP addresses, and public event content. • Google Play Services for app distribution. We do not integrate any analytics SDK, crash reporter, or advertising SDK.

• Local database is encrypted with a key derived from your PIN (Argon2id key derivation). • Message bodies are sealed with XChaCha20-Poly1305 under the channel's symmetric content key. The Ed25519 signature covers the ciphertext, so a forged body fails the signature check before decryption is attempted. • Identity secrets never leave the device. • Cleartext HTTP is disabled at the network layer; Nostr relays must use wss://.

If we change this policy we will update the effective date and post the new version at this URL (https://bluedefense.de/unblock/privacy).

For questions about this Privacy Policy or the Unblock app: Email: unblock-support@bluedefense.de Publisher: BlueDefense Address: Kleinschewskystraße 61, 12555 Berlin, Germany