Radar – Privacy Policy

📋 Overview

This Privacy Policy explains how DAL Technology (“we”, “our”, or “us”) collects, uses, stores, and shares information when you use the Radar Android application (package uk.co.daltechnology.radar).

By installing or using Radar you agree to the practices described in this policy. If you do not agree, please uninstall the app and do not use it.

📦 Information We Collect

The following categories of data are collected or accessed, depending on the features you use and the permissions you grant.

Data you provide directly

Data collected automatically

Data accessed with your permission

🗄️ What Our Server Stores — In Detail

Radar operates an Oracle-based backend server that enables peer discovery and message relay. The following explains precisely what is stored on that server, how long it is kept, and what we can and cannot see.

Peer location record

• One row per device UUID — no history, just the current position.
• Stores: UUID (pseudonymous), current GPS coordinates, optional nickname, optional gender, IP address, port, app version, FCM token, device model/OS.
• No email address or phone number is stored — this is a deliberate privacy design decision.
• The record is overwritten on every location update; previous locations are not retained.
• Soft-deleted when the device identity is reset; hard-deleted on the next nightly cleanup job.

Relayed messages

• Messages sent via the server relay are stored temporarily until the recipient collects them.
• Maximum retention: 7 days. Messages are soft-deleted as soon as all recipients acknowledge them, or when the 7-day TTL expires. The nightly job physically removes soft-deleted rows.
• Unencrypted relay messages: the server stores the full message JSON. We can technically read the payload. We do not do so except for operational support or legal obligations.
• Encrypted (sealed-sender) messages: the ciphertext is stored opaquely. We cannot decrypt or read the message content. The cipher used is X25519 / XChaCha20-Poly1305.
• The sender's UUID is stored in the outer message envelope of both encrypted and unencrypted messages (used for authentication / anti-spam). It is pseudonymous and not linked to any real-world identity.
• Recipient UUIDs are stored for routing and are pseudonymous.
• Push notification payload for sealed messages contains only a minimal wake-up signal ('message_pending') — no message content, no sender identity.

API request log

• Every API call is logged with: client IP address, sender UUID, action type, request timestamp, and the full request/response JSON.
• Used for debugging, security monitoring, and operational support.
• Log tables are partitioned by date and rotated by the nightly job.

Nonces

• Single-use cryptographic nonces are stored for up to 5 minutes to prevent replay attacks.
• No personal data is contained in nonces.

Support records

• Stores: sender UUID, support category, message text, optional reply-to email you provide.
• Retained until the support request is resolved.

⚙️ How We Use Your Information

We use the information described above only for the following purposes:

• To power the core peer discovery, messaging, and mapping features of Radar.
• To display your pseudonymous profile (nickname and gender) to nearby Radar peers.
• To relay messages between you and other Radar users when no direct wireless path is available.
• To send a minimal push notification to your device when a relayed message is waiting.
• To render maps and location features via Google Maps SDK and Google Play Services Location.
• To maintain the local encrypted database of your messages, contacts, and settings.
• To provide emergency features including GPS display, SOS signalling, and nearby-services lookup.
• To respond to in-app support requests you submit.
• To detect and prevent abuse, replay attacks, and unauthorised access to the API.

🤝 How We Share Your Information

Radar is designed to minimise data sharing. Information is shared only in the following limited circumstances.

Third-party services used by the app

With other Radar users (peer-to-peer and via relay)

• Your current location and pseudonymous profile (nickname, gender) are shared with nearby Radar peers via our server or direct wireless link.
• No email address or phone number is ever sent to other users.
• You control what profile information you provide — all profile fields except UUID are optional.

Legal requirements

• We may disclose information if required by law, court order, or governmental authority.
• We may also disclose information where necessary to protect our legal rights or the safety of any person.

⏱️ Data Retention & Deletion

🔒 Security

On-device security

• The local message and contact database is encrypted at rest using SQLCipher.
• Optional biometric lock (fingerprint / face authentication) before the app opens.
• Device UUID and cryptographic keys can be wiped and regenerated at any time via Settings → Device Identity Reset.

In-transit security

• All communication with the relay server uses HTTPS (TLS).
• API requests are authenticated with a pre-shared API key, a per-request timestamp, and a one-time-use nonce to prevent replay attacks.
• End-to-end encrypted messages use X25519 key exchange and XChaCha20-Poly1305 authenticated encryption — the server stores only the opaque ciphertext.
• The sealed-sender design means the server cannot determine the real-world identity of message participants from the encrypted payload alone.

Server-side security

• The relay server is an Oracle APEX / ORDS deployment.
• Requests older than 60 seconds are rejected (anti-replay).
• Single-use nonces prevent exact request replay.

🔑 Android Permissions Explained

Every Android permission declared in the app manifest is listed below with the reason it is needed.

📍 Location Data — Special Notice

Radar uses both foreground and background location. This is fundamental to the app's purpose: discovering nearby peers and keeping your position updated on the shared map even when the screen is off.

• Your current location is sent to our relay server and stored in one record per device (no history — each update overwrites the previous position).
• Location is shared with other Radar peers who query for nearby devices within your configured discovery range.
• Location is not used for advertising or profiling.
• You can disable location sharing at any time via the app's Privacy Settings or by revoking the location permission in Android Settings.
• A persistent foreground service notification is shown whenever background location is active, in compliance with Android requirements.

📱 SMS & MMS Integration

Radar can optionally act as an SMS/MMS client. This feature is entirely optional and off by default.

• The app reads your SMS inbox from the Android Telephony provider to display messages alongside Radar chats.
• Incoming SMS/MMS messages are received via system broadcast receivers.
• SMS/MMS content is stored locally in the encrypted on-device database only — it is never uploaded to our relay server.
• You can disable SMS integration at any time in Settings → SMS Integration.

🧑 Your Rights & Choices

You have the following controls over your data:

• Delete messages — delete individual messages, clear entire conversations, or wipe all chats from within the app.
• Delete contacts — remove any Radar contact from the contact card dialog.
• Reset device identity — Settings → Device Identity Reset destroys all cryptographic keys and generates a new UUID, severing all links to your previous identity on the server.
• Revoke permissions — revoke any permission (location, contacts, SMS, camera, microphone) at any time via Android Settings → Apps → Radar → Permissions.
• Block contacts — block any peer to stop all messages and presence updates from them.
• Delete all data — uninstalling the app removes all locally stored app data. Your server-side location record and any pending relay messages will be removed by the scheduled nightly cleanup.
• Export data — use Settings → Debug Info to view stored data; use Export Chat to export conversations.

GDPR / UK GDPR rights (EU/EEA and UK users)

• If you are in the EU/EEA or UK you may also have rights to: access, rectification, erasure, restriction of processing, and data portability.
• To exercise these rights contact us at support@daltechnology.co.uk.

🧒 Children's Privacy

Radar is not intended for children under the age of 13 (or the applicable minimum age in your jurisdiction). We do not knowingly collect personal information from children under 13.

If you are a parent or guardian and believe your child has provided us with personal information, please contact us at support@daltechnology.co.uk. We will take steps to delete such information as quickly as possible.

🔗 Third-Party Links & Services

The app may contain links to third-party websites or services (e.g. emergency services websites, hospital listings). We are not responsible for the privacy practices of those third parties.

The Matrix protocol allows you to connect to homeservers operated by third parties. Those homeservers are governed by their own privacy policies.

Google's use of data is governed by the Google Privacy Policy (https://policies.google.com/privacy).

📝 Changes to This Policy

We may update this Privacy Policy from time to time. When we do, we will revise the "Last updated" date at the top of this page and, where appropriate, notify you via an in-app notice.

Your continued use of Radar after any changes constitutes your acceptance of the revised policy. We encourage you to review this page periodically.